tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2015, The Linux Foundation. All rights reserved.
4 */
5
6#include <linux/etherdevice.h>
7
8#include "dsa_priv.h"
9
10#define QCA_HDR_LEN 2
11#define QCA_HDR_VERSION 0x2
12
13#define QCA_HDR_RECV_VERSION_MASK GENMASK(15, 14)
14#define QCA_HDR_RECV_VERSION_S 14
15#define QCA_HDR_RECV_PRIORITY_MASK GENMASK(13, 11)
16#define QCA_HDR_RECV_PRIORITY_S 11
17#define QCA_HDR_RECV_TYPE_MASK GENMASK(10, 6)
18#define QCA_HDR_RECV_TYPE_S 6
19#define QCA_HDR_RECV_FRAME_IS_TAGGED BIT(3)
20#define QCA_HDR_RECV_SOURCE_PORT_MASK GENMASK(2, 0)
21
22#define QCA_HDR_XMIT_VERSION_MASK GENMASK(15, 14)
23#define QCA_HDR_XMIT_VERSION_S 14
24#define QCA_HDR_XMIT_PRIORITY_MASK GENMASK(13, 11)
25#define QCA_HDR_XMIT_PRIORITY_S 11
26#define QCA_HDR_XMIT_CONTROL_MASK GENMASK(10, 8)
27#define QCA_HDR_XMIT_CONTROL_S 8
28#define QCA_HDR_XMIT_FROM_CPU BIT(7)
29#define QCA_HDR_XMIT_DP_BIT_MASK GENMASK(6, 0)
30
31static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
32{
33 struct dsa_port *dp = dsa_slave_to_port(dev);
34 __be16 *phdr;
35 u16 hdr;
36
37 if (skb_cow_head(skb, QCA_HDR_LEN) < 0)
38 return NULL;
39
40 skb_push(skb, QCA_HDR_LEN);
41
42 memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN);
43 phdr = (__be16 *)(skb->data + 2 * ETH_ALEN);
44
45 /* Set the version field, and set destination port information */
46 hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S |
47 QCA_HDR_XMIT_FROM_CPU | BIT(dp->index);
48
49 *phdr = htons(hdr);
50
51 return skb;
52}
53
54static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
55 struct packet_type *pt)
56{
57 u8 ver;
58 u16 hdr;
59 int port;
60 __be16 *phdr;
61
62 if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
63 return NULL;
64
65 /* The QCA header is added by the switch between src addr and Ethertype
66 * At this point, skb->data points to ethertype so header should be
67 * right before
68 */
69 phdr = (__be16 *)(skb->data - 2);
70 hdr = ntohs(*phdr);
71
72 /* Make sure the version is correct */
73 ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S;
74 if (unlikely(ver != QCA_HDR_VERSION))
75 return NULL;
76
77 /* Remove QCA tag and recalculate checksum */
78 skb_pull_rcsum(skb, QCA_HDR_LEN);
79 memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN,
80 ETH_HLEN - QCA_HDR_LEN);
81
82 /* Get source port information */
83 port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK);
84
85 skb->dev = dsa_master_find_slave(dev, 0, port);
86 if (!skb->dev)
87 return NULL;
88
89 return skb;
90}
91
92static const struct dsa_device_ops qca_netdev_ops = {
93 .name = "qca",
94 .proto = DSA_TAG_PROTO_QCA,
95 .xmit = qca_tag_xmit,
96 .rcv = qca_tag_rcv,
97 .overhead = QCA_HDR_LEN,
98};
99
100MODULE_LICENSE("GPL");
101MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_QCA);
102
103module_dsa_tag_driver(qca_netdev_ops);