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 "dsa_priv.h" 11 12 static struct sk_buff *xrs700x_xmit(struct sk_buff *skb, struct net_device *dev) 13 { 14 struct dsa_port *partner, *dp = dsa_slave_to_port(dev); 15 u8 *trailer; 16 17 trailer = skb_put(skb, 1); 18 trailer[0] = BIT(dp->index); 19 20 if (dp->hsr_dev) 21 dsa_hsr_foreach_port(partner, dp->ds, dp->hsr_dev) 22 if (partner != dp) 23 trailer[0] |= BIT(partner->index); 24 25 return skb; 26 } 27 28 static struct sk_buff *xrs700x_rcv(struct sk_buff *skb, struct net_device *dev, 29 struct packet_type *pt) 30 { 31 int source_port; 32 u8 *trailer; 33 34 trailer = skb_tail_pointer(skb) - 1; 35 36 source_port = ffs((int)trailer[0]) - 1; 37 38 if (source_port < 0) 39 return NULL; 40 41 skb->dev = dsa_master_find_slave(dev, 0, source_port); 42 if (!skb->dev) 43 return NULL; 44 45 if (pskb_trim_rcsum(skb, skb->len - 1)) 46 return NULL; 47 48 /* Frame is forwarded by hardware, don't forward in software. */ 49 skb->offload_fwd_mark = 1; 50 51 return skb; 52 } 53 54 static const struct dsa_device_ops xrs700x_netdev_ops = { 55 .name = "xrs700x", 56 .proto = DSA_TAG_PROTO_XRS700X, 57 .xmit = xrs700x_xmit, 58 .rcv = xrs700x_rcv, 59 .needed_tailroom = 1, 60 }; 61 62 MODULE_LICENSE("GPL"); 63 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_XRS700X); 64 65 module_dsa_tag_driver(xrs700x_netdev_ops); 66