Commit a08d6a6d authored by Clément Léger's avatar Clément Léger Committed by David S. Miller
Browse files

net: dsa: add Renesas RZ/N1 switch tag driver 



The switch that is present on the Renesas RZ/N1 SoC uses a specific
VLAN value followed by 6 bytes which contains forwarding configuration.

Signed-off-by: default avatarClément Léger <clement.leger@bootlin.com>
Reviewed-by: default avatarVladimir Oltean <olteanv@gmail.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 67f38b1c

include/net/dsa.h

+2 −0
Original line number Diff line number Diff line
@@ -53,6 +53,7 @@ struct phylink_link_state; 
#define DSA_TAG_PROTO_SJA1110_VALUE		23

#define DSA_TAG_PROTO_RTL8_4_VALUE		24

#define DSA_TAG_PROTO_RTL8_4T_VALUE		25

#define DSA_TAG_PROTO_RZN1_A5PSW_VALUE		26



enum dsa_tag_protocol {

	DSA_TAG_PROTO_NONE		= DSA_TAG_PROTO_NONE_VALUE,
@@ -81,6 +82,7 @@ enum dsa_tag_protocol { 
	DSA_TAG_PROTO_SJA1110		= DSA_TAG_PROTO_SJA1110_VALUE,

	DSA_TAG_PROTO_RTL8_4		= DSA_TAG_PROTO_RTL8_4_VALUE,

	DSA_TAG_PROTO_RTL8_4T		= DSA_TAG_PROTO_RTL8_4T_VALUE,

	DSA_TAG_PROTO_RZN1_A5PSW	= DSA_TAG_PROTO_RZN1_A5PSW_VALUE,

};



struct dsa_switch;

include/uapi/linux/if_ether.h

+1 −0
Original line number Diff line number Diff line
@@ -116,6 +116,7 @@ 
#define ETH_P_QINQ3	0x9300		/* deprecated QinQ VLAN [ NOT AN OFFICIALLY REGISTERED ID ] */

#define ETH_P_EDSA	0xDADA		/* Ethertype DSA [ NOT AN OFFICIALLY REGISTERED ID ] */

#define ETH_P_DSA_8021Q	0xDADB		/* Fake VLAN Header for DSA [ NOT AN OFFICIALLY REGISTERED ID ] */

#define ETH_P_DSA_A5PSW	0xE001		/* A5PSW Tag Value [ NOT AN OFFICIALLY REGISTERED ID ] */

#define ETH_P_IFE	0xED3E		/* ForCES inter-FE LFB type */

#define ETH_P_AF_IUCV   0xFBFB		/* IBM af_iucv [ NOT AN OFFICIALLY REGISTERED ID ] */

net/dsa/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -132,6 +132,13 @@ config NET_DSA_TAG_RTL8_4 
	  Say Y or M if you want to enable support for tagging frames for Realtek

	  switches with 8 byte protocol 4 tags, such as the Realtek RTL8365MB-VC.



config NET_DSA_TAG_RZN1_A5PSW

	tristate "Tag driver for Renesas RZ/N1 A5PSW switch"

	help

	  Say Y or M if you want to enable support for tagging frames for

	  Renesas RZ/N1 embedded switch that uses an 8 byte tag located after

	  destination MAC address.



config NET_DSA_TAG_LAN9303

	tristate "Tag driver for SMSC/Microchip LAN9303 family of switches"

	help

net/dsa/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ obj-$(CONFIG_NET_DSA_TAG_OCELOT_8021Q) += tag_ocelot_8021q.o 
obj-$(CONFIG_NET_DSA_TAG_QCA) += tag_qca.o

obj-$(CONFIG_NET_DSA_TAG_RTL4_A) += tag_rtl4_a.o

obj-$(CONFIG_NET_DSA_TAG_RTL8_4) += tag_rtl8_4.o

obj-$(CONFIG_NET_DSA_TAG_RZN1_A5PSW) += tag_rzn1_a5psw.o

obj-$(CONFIG_NET_DSA_TAG_SJA1105) += tag_sja1105.o

obj-$(CONFIG_NET_DSA_TAG_TRAILER) += tag_trailer.o

obj-$(CONFIG_NET_DSA_TAG_XRS700X) += tag_xrs700x.o

net/dsa/tag_rzn1_a5psw.c

0 → 100644
+113 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright (C) 2022 Schneider Electric

 *

 * Clément Léger <clement.leger@bootlin.com>

 */



#include <linux/bitfield.h>

#include <linux/etherdevice.h>

#include <linux/if_ether.h>

#include <net/dsa.h>



#include "dsa_priv.h"



/* To define the outgoing port and to discover the incoming port a TAG is

 * inserted after Src MAC :

 *

 *       Dest MAC       Src MAC           TAG         Type

 * ...| 1 2 3 4 5 6 | 1 2 3 4 5 6 | 1 2 3 4 5 6 7 8 | 1 2 |...

 *                                |<--------------->|

 *

 * See struct a5psw_tag for layout

 */



#define ETH_P_DSA_A5PSW			0xE001

#define A5PSW_TAG_LEN			8

#define A5PSW_CTRL_DATA_FORCE_FORWARD	BIT(0)

/* This is both used for xmit tag and rcv tagging */

#define A5PSW_CTRL_DATA_PORT		GENMASK(3, 0)



struct a5psw_tag {

	__be16 ctrl_tag;

	__be16 ctrl_data;

	__be16 ctrl_data2_hi;

	__be16 ctrl_data2_lo;

};



static struct sk_buff *a5psw_tag_xmit(struct sk_buff *skb, struct net_device *dev)

{

	struct dsa_port *dp = dsa_slave_to_port(dev);

	struct a5psw_tag *ptag;

	u32 data2_val;



	BUILD_BUG_ON(sizeof(*ptag) != A5PSW_TAG_LEN);



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

	 * least 60 bytes otherwise they will be discarded when they enter the

	 * switch port logic.

	 */

	if (__skb_put_padto(skb, ETH_ZLEN, false))

		return NULL;



	/* provide 'A5PSW_TAG_LEN' bytes additional space */

	skb_push(skb, A5PSW_TAG_LEN);



	/* make room between MACs and Ether-Type to insert tag */

	dsa_alloc_etype_header(skb, A5PSW_TAG_LEN);



	ptag = dsa_etype_header_pos_tx(skb);



	data2_val = FIELD_PREP(A5PSW_CTRL_DATA_PORT, BIT(dp->index));

	ptag->ctrl_tag = htons(ETH_P_DSA_A5PSW);

	ptag->ctrl_data = htons(A5PSW_CTRL_DATA_FORCE_FORWARD);

	ptag->ctrl_data2_lo = htons(data2_val);

	ptag->ctrl_data2_hi = 0;



	return skb;

}



static struct sk_buff *a5psw_tag_rcv(struct sk_buff *skb,

				     struct net_device *dev)

{

	struct a5psw_tag *tag;

	int port;



	if (unlikely(!pskb_may_pull(skb, A5PSW_TAG_LEN))) {

		dev_warn_ratelimited(&dev->dev,

				     "Dropping packet, cannot pull\n");

		return NULL;

	}



	tag = dsa_etype_header_pos_rx(skb);



	if (tag->ctrl_tag != htons(ETH_P_DSA_A5PSW)) {

		dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid TAG marker\n");

		return NULL;

	}



	port = FIELD_GET(A5PSW_CTRL_DATA_PORT, ntohs(tag->ctrl_data));



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

	if (!skb->dev)

		return NULL;



	skb_pull_rcsum(skb, A5PSW_TAG_LEN);

	dsa_strip_etype_header(skb, A5PSW_TAG_LEN);



	dsa_default_offload_fwd_mark(skb);



	return skb;

}



static const struct dsa_device_ops a5psw_netdev_ops = {

	.name	= "a5psw",

	.proto	= DSA_TAG_PROTO_RZN1_A5PSW,

	.xmit	= a5psw_tag_xmit,

	.rcv	= a5psw_tag_rcv,

	.needed_headroom = A5PSW_TAG_LEN,

};



MODULE_LICENSE("GPL v2");

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_A5PSW);

module_dsa_tag_driver(a5psw_netdev_ops);