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: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Kurt Kanzenbach 2020-11-03 08:10:54 +01:00 committed by Jakub Kicinski
parent 94f44f2883
commit 01ef09caad
4 changed files with 75 additions and 0 deletions

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@ -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;

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@ -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

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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
net/dsa/tag_hellcreek.c Normal file
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@ -0,0 +1,66 @@
// 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);