Commit 01ef09ca authored by Kurt Kanzenbach's avatar Kurt Kanzenbach Committed by Jakub Kicinski
Browse files

net: dsa: Add tag handling for Hirschmann Hellcreek switches



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: default avatarKurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: default avatarVladimir Oltean <olteanv@gmail.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 94f44f28
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+2 −0
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ struct phylink_link_state;
#define DSA_TAG_PROTO_OCELOT_VALUE		15
#define DSA_TAG_PROTO_AR9331_VALUE		16
#define DSA_TAG_PROTO_RTL4_A_VALUE		17
#define DSA_TAG_PROTO_HELLCREEK_VALUE		18

enum dsa_tag_protocol {
	DSA_TAG_PROTO_NONE		= DSA_TAG_PROTO_NONE_VALUE,
@@ -65,6 +66,7 @@ enum dsa_tag_protocol {
	DSA_TAG_PROTO_OCELOT		= DSA_TAG_PROTO_OCELOT_VALUE,
	DSA_TAG_PROTO_AR9331		= DSA_TAG_PROTO_AR9331_VALUE,
	DSA_TAG_PROTO_RTL4_A		= DSA_TAG_PROTO_RTL4_A_VALUE,
	DSA_TAG_PROTO_HELLCREEK		= DSA_TAG_PROTO_HELLCREEK_VALUE,
};

struct packet_type;
+6 −0
Original line number Diff line number Diff line
@@ -56,6 +56,12 @@ config NET_DSA_TAG_BRCM_PREPEND
	  Broadcom switches which places the tag before the Ethernet header
	  (prepended).

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.

config NET_DSA_TAG_GSWIP
	tristate "Tag driver for Lantiq / Intel GSWIP switches"
	help
+1 −0
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@@ -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-$(CONFIG_NET_DSA_TAG_RTL4_A) += tag_rtl4_a.o
obj-$(CONFIG_NET_DSA_TAG_LAN9303) += tag_lan9303.o
+66 −0
Original line number Diff line number Diff line
// 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 <kurt@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);
	u8 *tag;

	/* Tag encoding */
	tag  = skb_put(skb, HELLCREEK_TAG_LEN);
	*tag = BIT(dp->index);

	return skb;
}

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,
	.tail_tag = true,
};

MODULE_LICENSE("Dual MIT/GPL");
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_HELLCREEK);

module_dsa_tag_driver(hellcreek_netdev_ops);