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

include/net/dsa.h

+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;

net/dsa/Kconfig

+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

net/dsa/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

net/dsa/tag_hellcreek.c

0 → 100644
+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);