mirror of
https://github.com/torvalds/linux
synced 2024-07-21 10:41:44 +00:00
bd954b8260
It would be nice if tagging protocol drivers could include just the header they need, since they are (mostly) data path and isolated from most of the other DSA core code does. Create a tag.c and a tag.h file which are meant to support tagging protocol drivers. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
127 lines
3 KiB
C
127 lines
3 KiB
C
// 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.
|
|
*/
|
|
|
|
#include <linux/etherdevice.h>
|
|
#include <linux/bits.h>
|
|
|
|
#include "tag.h"
|
|
|
|
#define RTL4_A_NAME "rtl4a"
|
|
|
|
#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)
|
|
{
|
|
struct dsa_port *dp = dsa_slave_to_port(dev);
|
|
__be16 *p;
|
|
u8 *tag;
|
|
u16 out;
|
|
|
|
/* Pad out to at least 60 bytes */
|
|
if (unlikely(__skb_put_padto(skb, ETH_ZLEN, false)))
|
|
return NULL;
|
|
|
|
netdev_dbg(dev, "add realtek tag to package to port %d\n",
|
|
dp->index);
|
|
skb_push(skb, RTL4_A_HDR_LEN);
|
|
|
|
dsa_alloc_etype_header(skb, RTL4_A_HDR_LEN);
|
|
tag = dsa_etype_header_pos_tx(skb);
|
|
|
|
/* Set Ethertype */
|
|
p = (__be16 *)tag;
|
|
*p = htons(RTL4_A_ETHERTYPE);
|
|
|
|
out = (RTL4_A_PROTOCOL_RTL8366RB << RTL4_A_PROTOCOL_SHIFT);
|
|
/* The lower bits indicate the port number */
|
|
out |= BIT(dp->index);
|
|
|
|
p = (__be16 *)(tag + 2);
|
|
*p = htons(out);
|
|
|
|
return skb;
|
|
}
|
|
|
|
static struct sk_buff *rtl4a_tag_rcv(struct sk_buff *skb,
|
|
struct net_device *dev)
|
|
{
|
|
u16 protport;
|
|
__be16 *p;
|
|
u16 etype;
|
|
u8 *tag;
|
|
u8 prot;
|
|
u8 port;
|
|
|
|
if (unlikely(!pskb_may_pull(skb, RTL4_A_HDR_LEN)))
|
|
return NULL;
|
|
|
|
tag = dsa_etype_header_pos_rx(skb);
|
|
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);
|
|
|
|
dsa_strip_etype_header(skb, RTL4_A_HDR_LEN);
|
|
|
|
dsa_default_offload_fwd_mark(skb);
|
|
|
|
return skb;
|
|
}
|
|
|
|
static const struct dsa_device_ops rtl4a_netdev_ops = {
|
|
.name = RTL4_A_NAME,
|
|
.proto = DSA_TAG_PROTO_RTL4_A,
|
|
.xmit = rtl4a_tag_xmit,
|
|
.rcv = rtl4a_tag_rcv,
|
|
.needed_headroom = RTL4_A_HDR_LEN,
|
|
};
|
|
module_dsa_tag_driver(rtl4a_netdev_ops);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL4_A, RTL4_A_NAME);
|