The Hirschmann Hellcreek TSN switches have a special tagging protocol for frames
exchanged between the CPU port and the master interface. The format is a one
byte trailer indicating the destination or origin port.
It's quite similar to the Micrel KSZ tagging. That's why the implementation is
based on that code.
Signed-off-by: Kurt Kanzenbach <k...@linutronix.de>
---
include/net/dsa.h | 2 +
net/dsa/Kconfig | 6 +++
net/dsa/Makefile | 1 +
net/dsa/tag_hellcreek.c | 101 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 110 insertions(+)
create mode 100644 net/dsa/tag_hellcreek.c
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 50389772c597..2784c4851d92 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -44,6 +44,7 @@ struct phylink_link_state;
#define DSA_TAG_PROTO_KSZ8795_VALUE 14
#define DSA_TAG_PROTO_OCELOT_VALUE 15
#define DSA_TAG_PROTO_AR9331_VALUE 16
+#define DSA_TAG_PROTO_HELLCREEK_VALUE 17
enum dsa_tag_protocol {
DSA_TAG_PROTO_NONE = DSA_TAG_PROTO_NONE_VALUE,
@@ -63,6 +64,7 @@ enum dsa_tag_protocol {
DSA_TAG_PROTO_KSZ8795 = DSA_TAG_PROTO_KSZ8795_VALUE,
DSA_TAG_PROTO_OCELOT = DSA_TAG_PROTO_OCELOT_VALUE,
DSA_TAG_PROTO_AR9331 = DSA_TAG_PROTO_AR9331_VALUE,
+ DSA_TAG_PROTO_HELLCREEK = DSA_TAG_PROTO_HELLCREEK_VALUE,
};
struct packet_type;
diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index d5bc6ac599ef..edc0c3ab6a4e 100644
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -121,4 +121,10 @@ config NET_DSA_TAG_TRAILER
Say Y or M if you want to enable support for tagging frames at
with a trailed. e.g. Marvell 88E6060.
+config NET_DSA_TAG_HELLCREEK
+ tristate "Tag driver for Hirschmann Hellcreek TSN switches"
+ help
+ Say Y or M if you want to enable support for tagging frames
+ for the Hirschmann Hellcreek TSN switches.
+
endif
diff --git a/net/dsa/Makefile b/net/dsa/Makefile
index 108486cfdeef..ed72f4ea899b 100644
--- a/net/dsa/Makefile
+++ b/net/dsa/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_NET_DSA_TAG_BRCM_COMMON) += tag_brcm.o
obj-$(CONFIG_NET_DSA_TAG_DSA) += tag_dsa.o
obj-$(CONFIG_NET_DSA_TAG_EDSA) += tag_edsa.o
obj-$(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-$(CONFIG_NET_DSA_TAG_LAN9303) += tag_lan9303.o
obj-$(CONFIG_NET_DSA_TAG_MTK) += tag_mtk.o
diff --git a/net/dsa/tag_hellcreek.c b/net/dsa/tag_hellcreek.c
new file mode 100644
index 000000000000..0895eda94bb5
--- /dev/null
+++ b/net/dsa/tag_hellcreek.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * net/dsa/tag_hellcreek.c - Hirschmann Hellcreek switch tag format handling
+ *
+ * Copyright (C) 2019,2020 Linutronix GmbH
+ * Author Kurt Kanzenbach <k...@linutronix.de>
+ *
+ * Based on tag_ksz.c.
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <net/dsa.h>
+
+#include "dsa_priv.h"
+
+#define HELLCREEK_TAG_LEN 1
+
+static struct sk_buff *hellcreek_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct dsa_port *dp = dsa_slave_to_port(dev);
+ struct sk_buff *nskb;
+ int padlen;
+ u8 *tag;
+
+ padlen = (skb->len >= ETH_ZLEN) ? 0 : ETH_ZLEN - skb->len;
+
+ if (skb_tailroom(skb) >= padlen + HELLCREEK_TAG_LEN) {
+ /* Let dsa_slave_xmit() free skb */
+ if (__skb_put_padto(skb, skb->len + padlen, false))
+ return NULL;
+
+ nskb = skb;
+ } else {
+ nskb = alloc_skb(NET_IP_ALIGN + skb->len +
+ padlen + HELLCREEK_TAG_LEN, GFP_ATOMIC);
+ if (!nskb)
+ return NULL;
+ skb_reserve(nskb, NET_IP_ALIGN);
+
+ skb_reset_mac_header(nskb);
+ skb_set_network_header(nskb,
+ skb_network_header(skb) - skb->head);
+ skb_set_transport_header(nskb,
+ skb_transport_header(skb) - skb->head);
+ skb_copy_and_csum_dev(skb, skb_put(nskb, skb->len));
+
+ /* Let skb_put_padto() free nskb, and let dsa_slave_xmit() free
+ * skb
+ */
+ if (skb_put_padto(nskb, nskb->len + padlen))
+ return NULL;
+
+ consume_skb(skb);
+ }
+
+ if (!nskb)
+ return NULL;
+
+ /* Tag encoding */
+ tag = skb_put(nskb, HELLCREEK_TAG_LEN);
+ *tag = BIT(dp->index);
+
+ return nskb;
+}
+
+static struct sk_buff *hellcreek_rcv(struct sk_buff *skb,
+ struct net_device *dev,
+ struct packet_type *pt)
+{
+ /* Tag decoding */
+ u8 *tag = skb_tail_pointer(skb) - HELLCREEK_TAG_LEN;
+ unsigned int port = tag[0] & 0x03;
+
+ skb->dev = dsa_master_find_slave(dev, 0, port);
+ if (!skb->dev) {
+ netdev_warn(dev, "Failed to get source port: %d\n", port);
+ return NULL;
+ }
+
+ pskb_trim_rcsum(skb, skb->len - HELLCREEK_TAG_LEN);
+
+ skb->offload_fwd_mark = true;
+
+ return skb;
+}
+
+static const struct dsa_device_ops hellcreek_netdev_ops = {
+ .name = "hellcreek",
+ .proto = DSA_TAG_PROTO_HELLCREEK,
+ .xmit = hellcreek_xmit,
+ .rcv = hellcreek_rcv,
+ .overhead = HELLCREEK_TAG_LEN,
+};
+
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_HELLCREEK);
+
+module_dsa_tag_driver(hellcreek_netdev_ops);
--
2.20.1
