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 u16 *phdr, hdr;
35
36 dev->stats.tx_packets++;
37 dev->stats.tx_bytes += skb->len;
38
39 if (skb_cow_head(skb, 0) < 0)
40 return NULL;
41
42 skb_push(skb, QCA_HDR_LEN);
43
44 memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN);
45 phdr = (u16 *)(skb->data + 2 * ETH_ALEN);
46
47 /* Set the version field, and set destination port information */
48 hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S |
49 QCA_HDR_XMIT_FROM_CPU | BIT(dp->index);
50
51 *phdr = htons(hdr);
52
53 return skb;
54}
55
56static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
57 struct packet_type *pt)
58{
59 u8 ver;
60 int port;
61 __be16 *phdr, hdr;
62
63 if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
64 return NULL;
65
66 /* The QCA header is added by the switch between src addr and Ethertype
67 * At this point, skb->data points to ethertype so header should be
68 * right before
69 */
70 phdr = (__be16 *)(skb->data - 2);
71 hdr = ntohs(*phdr);
72
73 /* Make sure the version is correct */
74 ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S;
75 if (unlikely(ver != QCA_HDR_VERSION))
76 return NULL;
77
78 /* Remove QCA tag and recalculate checksum */
79 skb_pull_rcsum(skb, QCA_HDR_LEN);
80 memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN,
81 ETH_HLEN - QCA_HDR_LEN);
82
83 /* Get source port information */
84 port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK);
85
86 skb->dev = dsa_master_find_slave(dev, 0, port);
87 if (!skb->dev)
88 return NULL;
89
90 return skb;
91}
92
93static int qca_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto,
94 int *offset)
95{
96 *offset = QCA_HDR_LEN;
97 *proto = ((__be16 *)skb->data)[0];
98
99 return 0;
100}
101
102static const struct dsa_device_ops qca_netdev_ops = {
103 .name = "qca",
104 .proto = DSA_TAG_PROTO_QCA,
105 .xmit = qca_tag_xmit,
106 .rcv = qca_tag_rcv,
107 .flow_dissect = qca_tag_flow_dissect,
108 .overhead = QCA_HDR_LEN,
109};
110
111MODULE_LICENSE("GPL");
112MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_QCA);
113
114module_dsa_tag_driver(qca_netdev_ops);