1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * XRS700x tag format handling
4 * Copyright (c) 2008-2009 Marvell Semiconductor
5 * Copyright (c) 2020 NovaTech LLC
6 */
7
8 #include <linux/bitops.h>
9
10 #include "tag.h"
11
12 #define XRS700X_NAME "xrs700x"
13
xrs700x_xmit(struct sk_buff * skb,struct net_device * dev)14 static struct sk_buff *xrs700x_xmit(struct sk_buff *skb, struct net_device *dev)
15 {
16 u8 *trailer;
17
18 trailer = skb_put(skb, 1);
19 trailer[0] = dsa_xmit_port_mask(skb, dev);
20
21 return skb;
22 }
23
xrs700x_rcv(struct sk_buff * skb,struct net_device * dev)24 static struct sk_buff *xrs700x_rcv(struct sk_buff *skb, struct net_device *dev)
25 {
26 int source_port;
27 u8 *trailer;
28
29 trailer = skb_tail_pointer(skb) - 1;
30
31 source_port = ffs((int)trailer[0]) - 1;
32
33 if (source_port < 0)
34 return NULL;
35
36 skb->dev = dsa_conduit_find_user(dev, 0, source_port);
37 if (!skb->dev)
38 return NULL;
39
40 if (pskb_trim_rcsum(skb, skb->len - 1))
41 return NULL;
42
43 /* Frame is forwarded by hardware, don't forward in software. */
44 dsa_default_offload_fwd_mark(skb);
45
46 return skb;
47 }
48
49 static const struct dsa_device_ops xrs700x_netdev_ops = {
50 .name = XRS700X_NAME,
51 .proto = DSA_TAG_PROTO_XRS700X,
52 .xmit = xrs700x_xmit,
53 .rcv = xrs700x_rcv,
54 .needed_tailroom = 1,
55 };
56
57 MODULE_DESCRIPTION("DSA tag driver for XRS700x switches");
58 MODULE_LICENSE("GPL");
59 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_XRS700X, XRS700X_NAME);
60
61 module_dsa_tag_driver(xrs700x_netdev_ops);
62