1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (c) 2019 Pengutronix, Oleksij Rempel <kernel@pengutronix.de> |
4 | */ |
5 | |
6 | |
7 | #include <linux/bitfield.h> |
8 | #include <linux/etherdevice.h> |
9 | |
10 | #include "tag.h" |
11 | |
12 | #define AR9331_NAME "ar9331" |
13 | |
14 | #define AR9331_HDR_LEN 2 |
15 | #define AR9331_HDR_VERSION 1 |
16 | |
17 | #define AR9331_HDR_VERSION_MASK GENMASK(15, 14) |
18 | #define AR9331_HDR_PRIORITY_MASK GENMASK(13, 12) |
19 | #define AR9331_HDR_TYPE_MASK GENMASK(10, 8) |
20 | #define AR9331_HDR_BROADCAST BIT(7) |
21 | #define AR9331_HDR_FROM_CPU BIT(6) |
22 | /* AR9331_HDR_RESERVED - not used or may be version field. |
23 | * According to the AR8216 doc it should 0b10. On AR9331 it is 0b11 on RX path |
24 | * and should be set to 0b11 to make it work. |
25 | */ |
26 | #define AR9331_HDR_RESERVED_MASK GENMASK(5, 4) |
27 | #define AR9331_HDR_PORT_NUM_MASK GENMASK(3, 0) |
28 | |
29 | static struct sk_buff *ar9331_tag_xmit(struct sk_buff *skb, |
30 | struct net_device *dev) |
31 | { |
32 | struct dsa_port *dp = dsa_user_to_port(dev); |
33 | __le16 *phdr; |
34 | u16 hdr; |
35 | |
36 | phdr = skb_push(skb, AR9331_HDR_LEN); |
37 | |
38 | hdr = FIELD_PREP(AR9331_HDR_VERSION_MASK, AR9331_HDR_VERSION); |
39 | hdr |= AR9331_HDR_FROM_CPU | dp->index; |
40 | /* 0b10 for AR8216 and 0b11 for AR9331 */ |
41 | hdr |= AR9331_HDR_RESERVED_MASK; |
42 | |
43 | phdr[0] = cpu_to_le16(hdr); |
44 | |
45 | return skb; |
46 | } |
47 | |
48 | static struct sk_buff *ar9331_tag_rcv(struct sk_buff *skb, |
49 | struct net_device *ndev) |
50 | { |
51 | u8 ver, port; |
52 | u16 hdr; |
53 | |
54 | if (unlikely(!pskb_may_pull(skb, AR9331_HDR_LEN))) |
55 | return NULL; |
56 | |
57 | hdr = le16_to_cpu(*(__le16 *)skb_mac_header(skb)); |
58 | |
59 | ver = FIELD_GET(AR9331_HDR_VERSION_MASK, hdr); |
60 | if (unlikely(ver != AR9331_HDR_VERSION)) { |
61 | netdev_warn_once(ndev, "%s:%i wrong header version 0x%2x\n" , |
62 | __func__, __LINE__, hdr); |
63 | return NULL; |
64 | } |
65 | |
66 | if (unlikely(hdr & AR9331_HDR_FROM_CPU)) { |
67 | netdev_warn_once(ndev, "%s:%i packet should not be from cpu 0x%2x\n" , |
68 | __func__, __LINE__, hdr); |
69 | return NULL; |
70 | } |
71 | |
72 | skb_pull_rcsum(skb, AR9331_HDR_LEN); |
73 | |
74 | /* Get source port information */ |
75 | port = FIELD_GET(AR9331_HDR_PORT_NUM_MASK, hdr); |
76 | |
77 | skb->dev = dsa_conduit_find_user(dev: ndev, device: 0, port); |
78 | if (!skb->dev) |
79 | return NULL; |
80 | |
81 | return skb; |
82 | } |
83 | |
84 | static const struct dsa_device_ops ar9331_netdev_ops = { |
85 | .name = AR9331_NAME, |
86 | .proto = DSA_TAG_PROTO_AR9331, |
87 | .xmit = ar9331_tag_xmit, |
88 | .rcv = ar9331_tag_rcv, |
89 | .needed_headroom = AR9331_HDR_LEN, |
90 | }; |
91 | |
92 | MODULE_DESCRIPTION("DSA tag driver for Atheros AR9331 SoC with built-in switch" ); |
93 | MODULE_LICENSE("GPL v2" ); |
94 | MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_AR9331, AR9331_NAME); |
95 | module_dsa_tag_driver(ar9331_netdev_ops); |
96 | |