tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (c) 2015, The Linux Foundation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 and
6 * only version 2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 */
13
14#include <linux/etherdevice.h>
15
16#include "dsa_priv.h"
17
18#define QCA_HDR_LEN 2
19#define QCA_HDR_VERSION 0x2
20
21#define QCA_HDR_RECV_VERSION_MASK GENMASK(15, 14)
22#define QCA_HDR_RECV_VERSION_S 14
23#define QCA_HDR_RECV_PRIORITY_MASK GENMASK(13, 11)
24#define QCA_HDR_RECV_PRIORITY_S 11
25#define QCA_HDR_RECV_TYPE_MASK GENMASK(10, 6)
26#define QCA_HDR_RECV_TYPE_S 6
27#define QCA_HDR_RECV_FRAME_IS_TAGGED BIT(3)
28#define QCA_HDR_RECV_SOURCE_PORT_MASK GENMASK(2, 0)
29
30#define QCA_HDR_XMIT_VERSION_MASK GENMASK(15, 14)
31#define QCA_HDR_XMIT_VERSION_S 14
32#define QCA_HDR_XMIT_PRIORITY_MASK GENMASK(13, 11)
33#define QCA_HDR_XMIT_PRIORITY_S 11
34#define QCA_HDR_XMIT_CONTROL_MASK GENMASK(10, 8)
35#define QCA_HDR_XMIT_CONTROL_S 8
36#define QCA_HDR_XMIT_FROM_CPU BIT(7)
37#define QCA_HDR_XMIT_DP_BIT_MASK GENMASK(6, 0)
38
39static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
40{
41 struct dsa_slave_priv *p = netdev_priv(dev);
42 u16 *phdr, hdr;
43
44 dev->stats.tx_packets++;
45 dev->stats.tx_bytes += skb->len;
46
47 if (skb_cow_head(skb, 0) < 0)
48 return NULL;
49
50 skb_push(skb, QCA_HDR_LEN);
51
52 memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN);
53 phdr = (u16 *)(skb->data + 2 * ETH_ALEN);
54
55 /* Set the version field, and set destination port information */
56 hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S |
57 QCA_HDR_XMIT_FROM_CPU |
58 BIT(p->dp->index);
59
60 *phdr = htons(hdr);
61
62 return skb;
63}
64
65static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
66 struct packet_type *pt)
67{
68 struct dsa_switch_tree *dst = dev->dsa_ptr;
69 struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
70 struct dsa_switch *ds;
71 u8 ver;
72 int port;
73 __be16 *phdr, hdr;
74
75 if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
76 return NULL;
77
78 /* The QCA header is added by the switch between src addr and Ethertype
79 * At this point, skb->data points to ethertype so header should be
80 * right before
81 */
82 phdr = (__be16 *)(skb->data - 2);
83 hdr = ntohs(*phdr);
84
85 /* Make sure the version is correct */
86 ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S;
87 if (unlikely(ver != QCA_HDR_VERSION))
88 return NULL;
89
90 /* Remove QCA tag and recalculate checksum */
91 skb_pull_rcsum(skb, QCA_HDR_LEN);
92 memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN,
93 ETH_HLEN - QCA_HDR_LEN);
94
95 /* This protocol doesn't support cascading multiple switches so it's
96 * safe to assume the switch is first in the tree
97 */
98 ds = cpu_dp->ds;
99 if (!ds)
100 return NULL;
101
102 /* Get source port information */
103 port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK);
104 if (!ds->ports[port].netdev)
105 return NULL;
106
107 /* Update skb & forward the frame accordingly */
108 skb->dev = ds->ports[port].netdev;
109
110 return skb;
111}
112
113const struct dsa_device_ops qca_netdev_ops = {
114 .xmit = qca_tag_xmit,
115 .rcv = qca_tag_rcv,
116};