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
qca_tag_xmit(struct sk_buff * skb,struct net_device * dev)31 static 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 skb_push(skb, QCA_HDR_LEN);
38
39 memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN);
40 phdr = (__be16 *)(skb->data + 2 * ETH_ALEN);
41
42 /* Set the version field, and set destination port information */
43 hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S |
44 QCA_HDR_XMIT_FROM_CPU | BIT(dp->index);
45
46 *phdr = htons(hdr);
47
48 return skb;
49 }
50
qca_tag_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt)51 static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
52 struct packet_type *pt)
53 {
54 u8 ver;
55 u16 hdr;
56 int port;
57 __be16 *phdr;
58
59 if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
60 return NULL;
61
62 /* The QCA header is added by the switch between src addr and Ethertype
63 * At this point, skb->data points to ethertype so header should be
64 * right before
65 */
66 phdr = (__be16 *)(skb->data - 2);
67 hdr = ntohs(*phdr);
68
69 /* Make sure the version is correct */
70 ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S;
71 if (unlikely(ver != QCA_HDR_VERSION))
72 return NULL;
73
74 /* Remove QCA tag and recalculate checksum */
75 skb_pull_rcsum(skb, QCA_HDR_LEN);
76 memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN,
77 ETH_HLEN - QCA_HDR_LEN);
78
79 /* Get source port information */
80 port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK);
81
82 skb->dev = dsa_master_find_slave(dev, 0, port);
83 if (!skb->dev)
84 return NULL;
85
86 return skb;
87 }
88
89 static const struct dsa_device_ops qca_netdev_ops = {
90 .name = "qca",
91 .proto = DSA_TAG_PROTO_QCA,
92 .xmit = qca_tag_xmit,
93 .rcv = qca_tag_rcv,
94 .overhead = QCA_HDR_LEN,
95 };
96
97 MODULE_LICENSE("GPL");
98 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_QCA);
99
100 module_dsa_tag_driver(qca_netdev_ops);
101