Commit 964dbf18 authored by Álvaro Fernández Rojas's avatar Álvaro Fernández Rojas Committed by David S. Miller
Browse files

net: dsa: tag_brcm: add support for legacy tags 



Add support for legacy Broadcom tags, which are similar to DSA_TAG_PROTO_BRCM.
These tags are used on BCM5325, BCM5365 and BCM63xx switches.

Signed-off-by: default avatarÁlvaro Fernández Rojas <noltari@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 73a2218c

include/net/dsa.h

+2 −0
Original line number Diff line number Diff line
@@ -49,10 +49,12 @@ struct phylink_link_state; 
#define DSA_TAG_PROTO_XRS700X_VALUE		19

#define DSA_TAG_PROTO_OCELOT_8021Q_VALUE	20

#define DSA_TAG_PROTO_SEVILLE_VALUE		21

#define DSA_TAG_PROTO_BRCM_LEGACY_VALUE		22



enum dsa_tag_protocol {

	DSA_TAG_PROTO_NONE		= DSA_TAG_PROTO_NONE_VALUE,

	DSA_TAG_PROTO_BRCM		= DSA_TAG_PROTO_BRCM_VALUE,

	DSA_TAG_PROTO_BRCM_LEGACY	= DSA_TAG_PROTO_BRCM_LEGACY_VALUE,

	DSA_TAG_PROTO_BRCM_PREPEND	= DSA_TAG_PROTO_BRCM_PREPEND_VALUE,

	DSA_TAG_PROTO_DSA		= DSA_TAG_PROTO_DSA_VALUE,

	DSA_TAG_PROTO_EDSA		= DSA_TAG_PROTO_EDSA_VALUE,

net/dsa/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -48,6 +48,13 @@ config NET_DSA_TAG_BRCM 
	  Say Y if you want to enable support for tagging frames for the

	  Broadcom switches which place the tag after the MAC source address.



config NET_DSA_TAG_BRCM_LEGACY

	tristate "Tag driver for Broadcom legacy switches using in-frame headers"

	select NET_DSA_TAG_BRCM_COMMON

	help

	  Say Y if you want to enable support for tagging frames for the

	  Broadcom legacy switches which place the tag after the MAC source

	  address.



config NET_DSA_TAG_BRCM_PREPEND

	tristate "Tag driver for Broadcom switches using prepended headers"

net/dsa/tag_brcm.c

+104 −3
Original line number Diff line number Diff line
@@ -12,9 +12,26 @@ 


#include "dsa_priv.h"



/* This tag length is 4 bytes, older ones were 6 bytes, we do not

 * handle them

 */

/* Legacy Broadcom tag (6 bytes) */

#define BRCM_LEG_TAG_LEN	6



/* Type fields */

/* 1st byte in the tag */

#define BRCM_LEG_TYPE_HI	0x88

/* 2nd byte in the tag */

#define BRCM_LEG_TYPE_LO	0x74



/* Tag fields */

/* 3rd byte in the tag */

#define BRCM_LEG_UNICAST	(0 << 5)

#define BRCM_LEG_MULTICAST	(1 << 5)

#define BRCM_LEG_EGRESS		(2 << 5)

#define BRCM_LEG_INGRESS	(3 << 5)



/* 6th byte in the tag */

#define BRCM_LEG_PORT_ID	(0xf)



/* Newer Broadcom tag (4 bytes) */

#define BRCM_TAG_LEN	4



/* Tag is constructed and desconstructed using byte by byte access
@@ -195,6 +212,87 @@ DSA_TAG_DRIVER(brcm_netdev_ops); 
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM);

#endif



#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY)

static struct sk_buff *brcm_leg_tag_xmit(struct sk_buff *skb,

					 struct net_device *dev)

{

	struct dsa_port *dp = dsa_slave_to_port(dev);

	u8 *brcm_tag;



	/* The Ethernet switch we are interfaced with needs packets to be at

	 * least 64 bytes (including FCS) otherwise they will be discarded when

	 * they enter the switch port logic. When Broadcom tags are enabled, we

	 * need to make sure that packets are at least 70 bytes

	 * (including FCS and tag) because the length verification is done after

	 * the Broadcom tag is stripped off the ingress packet.

	 *

	 * Let dsa_slave_xmit() free the SKB

	 */

	if (__skb_put_padto(skb, ETH_ZLEN + BRCM_LEG_TAG_LEN, false))

		return NULL;



	skb_push(skb, BRCM_LEG_TAG_LEN);



	memmove(skb->data, skb->data + BRCM_LEG_TAG_LEN, 2 * ETH_ALEN);



	brcm_tag = skb->data + 2 * ETH_ALEN;



	/* Broadcom tag type */

	brcm_tag[0] = BRCM_LEG_TYPE_HI;

	brcm_tag[1] = BRCM_LEG_TYPE_LO;



	/* Broadcom tag value */

	brcm_tag[2] = BRCM_LEG_EGRESS;

	brcm_tag[3] = 0;

	brcm_tag[4] = 0;

	brcm_tag[5] = dp->index & BRCM_LEG_PORT_ID;



	return skb;

}



static struct sk_buff *brcm_leg_tag_rcv(struct sk_buff *skb,

					struct net_device *dev,

					struct packet_type *pt)

{

	int source_port;

	u8 *brcm_tag;



	if (unlikely(!pskb_may_pull(skb, BRCM_LEG_PORT_ID)))

		return NULL;



	brcm_tag = skb->data - 2;



	source_port = brcm_tag[5] & BRCM_LEG_PORT_ID;



	skb->dev = dsa_master_find_slave(dev, 0, source_port);

	if (!skb->dev)

		return NULL;



	/* Remove Broadcom tag and update checksum */

	skb_pull_rcsum(skb, BRCM_LEG_TAG_LEN);



	skb->offload_fwd_mark = 1;



	/* Move the Ethernet DA and SA */

	memmove(skb->data - ETH_HLEN,

		skb->data - ETH_HLEN - BRCM_LEG_TAG_LEN,

		2 * ETH_ALEN);



	return skb;

}



static const struct dsa_device_ops brcm_legacy_netdev_ops = {

	.name = "brcm-legacy",

	.proto = DSA_TAG_PROTO_BRCM_LEGACY,

	.xmit = brcm_leg_tag_xmit,

	.rcv = brcm_leg_tag_rcv,

	.overhead = BRCM_LEG_TAG_LEN,

};



DSA_TAG_DRIVER(brcm_legacy_netdev_ops);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_LEGACY);

#endif /* CONFIG_NET_DSA_TAG_BRCM_LEGACY */



#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND)

static struct sk_buff *brcm_tag_xmit_prepend(struct sk_buff *skb,

					     struct net_device *dev)
@@ -227,6 +325,9 @@ static struct dsa_tag_driver *dsa_tag_driver_array[] = { 
#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM)

	&DSA_TAG_DRIVER_NAME(brcm_netdev_ops),

#endif

#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY)

	&DSA_TAG_DRIVER_NAME(brcm_legacy_netdev_ops),

#endif

#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND)

	&DSA_TAG_DRIVER_NAME(brcm_prepend_netdev_ops),

#endif