iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge branch 'RTL8366RB-tagging-support'

Browse Source 
Linus Walleij says:

====================
RTL8366RB tagging support

This patch set adds DSA tagging support to the RTL8366RB
DSA driver.

There is a minor performance improvement in the tag parser
compared to the previous patch set and the review tags
have been collected.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2020-07-08 15:36:19 -07:00
commit 32e0d42a16
6 changed files with 149 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/net/dsa/Kconfig
View File

@ -70,6 +70,7 @@ config NET_DSA_QCA8K
config NET_DSA_REALTEK_SMI
tristate "Realtek SMI Ethernet switch family support"
depends on NET_DSA
select NET_DSA_TAG_RTL4_A
select FIXED_PHY
select IRQ_DOMAIN
select REALTEK_PHY

31
drivers/net/dsa/rtl8366rb.c
View File

@ -109,8 +109,8 @@
/* CPU port control reg */
#define RTL8368RB_CPU_CTRL_REG 0x0061
#define RTL8368RB_CPU_PORTS_MSK 0x00FF
/* Enables inserting custom tag length/type 0x8899 */
#define RTL8368RB_CPU_INSTAG BIT(15)
/* Disables inserting custom tag length/type 0x8899 */
#define RTL8368RB_CPU_NO_TAG BIT(15)
#define RTL8366RB_SMAR0 0x0070 /* bits 0..15 */
#define RTL8366RB_SMAR1 0x0071 /* bits 16..31 */
@ -844,16 +844,14 @@ static int rtl8366rb_setup(struct dsa_switch *ds)
if (ret)
return ret;
/* Enable CPU port and enable inserting CPU tag
/* Enable CPU port with custom DSA tag 8899.
*
* Disabling RTL8368RB_CPU_INSTAG here will change the behaviour
* of the switch totally and it will start talking Realtek RRCP
* internally. It is probably possible to experiment with this,
* but then the kernel needs to understand and handle RRCP first.
* If you set RTL8368RB_CPU_NO_TAG (bit 15) in this registers
* the custom tag is turned off.
*/
ret = regmap_update_bits(smi->map, RTL8368RB_CPU_CTRL_REG,
0xFFFF,
RTL8368RB_CPU_INSTAG | BIT(smi->cpu_port));
BIT(smi->cpu_port));
if (ret)
return ret;
@ -967,21 +965,8 @@ static enum dsa_tag_protocol rtl8366_get_tag_protocol(struct dsa_switch *ds,
int port,
enum dsa_tag_protocol mp)
{
/* For now, the RTL switches are handled without any custom tags.
*
* It is possible to turn on "custom tags" by removing the
* RTL8368RB_CPU_INSTAG flag when enabling the port but what it
* does is unfamiliar to DSA: ethernet frames of type 8899, the Realtek
* Remote Control Protocol (RRCP) start to appear on the CPU port of
* the device. So this is not the ordinary few extra bytes in the
* frame. Instead it appears that the switch starts to talk Realtek
* RRCP internally which means a pretty complex RRCP implementation
* decoding and responding the RRCP protocol is needed to exploit this.
*
* The OpenRRCP project (dormant since 2009) have reverse-egineered
* parts of the protocol.
*/
return DSA_TAG_PROTO_NONE;
/* This switch uses the 4 byte protocol A Realtek DSA tag */
return DSA_TAG_PROTO_RTL4_A;
}
static void rtl8366rb_adjust_link(struct dsa_switch *ds, int port,

2
include/net/dsa.h
View File

@ -44,6 +44,7 @@ struct phylink_link_state;
#define DSA_TAG_PROTO_KSZ8795_VALUE 14
#define DSA_TAG_PROTO_OCELOT_VALUE 15
#define DSA_TAG_PROTO_AR9331_VALUE 16
#define DSA_TAG_PROTO_RTL4_A_VALUE 17
enum dsa_tag_protocol {
DSA_TAG_PROTO_NONE = DSA_TAG_PROTO_NONE_VALUE,
@ -63,6 +64,7 @@ enum dsa_tag_protocol {
DSA_TAG_PROTO_KSZ8795 = DSA_TAG_PROTO_KSZ8795_VALUE,
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,
};
struct packet_type;

7
net/dsa/Kconfig
View File

@ -86,6 +86,13 @@ config NET_DSA_TAG_KSZ
Say Y if you want to enable support for tagging frames for the
Microchip 8795/9477/9893 families of switches.
config NET_DSA_TAG_RTL4_A
tristate "Tag driver for Realtek 4 byte protocol A tags"
help
Say Y or M if you want to enable support for tagging frames for the
Realtek switches with 4 byte protocol A tags, sich as found in
the Realtek RTL8366RB.
config NET_DSA_TAG_OCELOT
tristate "Tag driver for Ocelot family of switches"
select PACKING

1
net/dsa/Makefile
View File

@ -11,6 +11,7 @@ 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_KSZ) += tag_ksz.o
obj-$(CONFIG_NET_DSA_TAG_RTL4_A) += tag_rtl4_a.o
obj-$(CONFIG_NET_DSA_TAG_LAN9303) += tag_lan9303.o
obj-$(CONFIG_NET_DSA_TAG_MTK) += tag_mtk.o
obj-$(CONFIG_NET_DSA_TAG_OCELOT) += tag_ocelot.o

130
net/dsa/tag_rtl4_a.c Normal file
View File

@ -0,0 +1,130 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Handler for Realtek 4 byte DSA switch tags
* Currently only supports protocol "A" found in RTL8366RB
* Copyright (c) 2020 Linus Walleij <linus.walleij@linaro.org>
*
* This "proprietary tag" header looks like so:
*
* -------------------------------------------------
* | MAC DA | MAC SA | 0x8899 | 2 bytes tag | Type |
* -------------------------------------------------
*
* The 2 bytes tag form a 16 bit big endian word. The exact
* meaning has been guessed from packet dumps from ingress
* frames, as no working egress traffic has been available
* we do not know the format of the egress tags or if they
* are even supported.
*/
#include <linux/etherdevice.h>
#include <linux/bits.h>
#include "dsa_priv.h"
#define RTL4_A_HDR_LEN 4
#define RTL4_A_ETHERTYPE 0x8899
#define RTL4_A_PROTOCOL_SHIFT 12
/*
* 0x1 = Realtek Remote Control protocol (RRCP)
* 0x2/0x3 seems to be used for loopback testing
* 0x9 = RTL8306 DSA protocol
* 0xa = RTL8366RB DSA protocol
*/
#define RTL4_A_PROTOCOL_RTL8366RB 0xa
static struct sk_buff *rtl4a_tag_xmit(struct sk_buff *skb,
struct net_device *dev)
{
/*
* Just let it pass thru, we don't know if it is possible
* to tag a frame with the 0x8899 ethertype and direct it
* to a specific port, all attempts at reverse-engineering have
* ended up with the frames getting dropped.
*
* The VLAN set-up needs to restrict the frames to the right port.
*
* If you have documentation on the tagging format for RTL8366RB
* (tag type A) then please contribute.
*/
return skb;
}
static struct sk_buff *rtl4a_tag_rcv(struct sk_buff *skb,
struct net_device *dev,
struct packet_type *pt)
{
u16 protport;
__be16 *p;
u16 etype;
u8 *tag;
u8 prot;
u8 port;
if (unlikely(!pskb_may_pull(skb, RTL4_A_HDR_LEN)))
return NULL;
/* The RTL4 header has its own custom Ethertype 0x8899 and that
* starts right at the beginning of the packet, after the src
* ethernet addr. Apparantly skb->data always points 2 bytes in,
* behind the Ethertype.
*/
tag = skb->data - 2;
p = (__be16 *)tag;
etype = ntohs(*p);
if (etype != RTL4_A_ETHERTYPE) {
/* Not custom, just pass through */
netdev_dbg(dev, "non-realtek ethertype 0x%04x\n", etype);
return skb;
}
p = (__be16 *)(tag + 2);
protport = ntohs(*p);
/* The 4 upper bits are the protocol */
prot = (protport >> RTL4_A_PROTOCOL_SHIFT) & 0x0f;
if (prot != RTL4_A_PROTOCOL_RTL8366RB) {
netdev_err(dev, "unknown realtek protocol 0x%01x\n", prot);
return NULL;
}
port = protport & 0xff;
skb->dev = dsa_master_find_slave(dev, 0, port);
if (!skb->dev) {
netdev_dbg(dev, "could not find slave for port %d\n", port);
return NULL;
}
/* Remove RTL4 tag and recalculate checksum */
skb_pull_rcsum(skb, RTL4_A_HDR_LEN);
/* Move ethernet DA and SA in front of the data */
memmove(skb->data - ETH_HLEN,
skb->data - ETH_HLEN - RTL4_A_HDR_LEN,
2 * ETH_ALEN);
skb->offload_fwd_mark = 1;
return skb;
}
static int rtl4a_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto,
int *offset)
{
*offset = RTL4_A_HDR_LEN;
/* Skip past the tag and fetch the encapsulated Ethertype */
*proto = ((__be16 *)skb->data)[1];
return 0;
}
static const struct dsa_device_ops rtl4a_netdev_ops = {
.name = "rtl4a",
.proto = DSA_TAG_PROTO_RTL4_A,
.xmit = rtl4a_tag_xmit,
.rcv = rtl4a_tag_rcv,
.flow_dissect = rtl4a_tag_flow_dissect,
.overhead = RTL4_A_HDR_LEN,
};
module_dsa_tag_driver(rtl4a_netdev_ops);
MODULE_LICENSE("GPL");
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL4_A);