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 { 30 int source_port; 31 u8 *trailer; 32 33 trailer = skb_tail_pointer(skb) - 1; 34 35 source_port = ffs((int)trailer[0]) - 1; 36 37 if (source_port < 0) 38 return NULL; 39 40 skb->dev = dsa_master_find_slave(dev, 0, source_port); 41 if (!skb->dev) 42 return NULL; 43 44 if (pskb_trim_rcsum(skb, skb->len - 1)) 45 return NULL; 46 47 /* Frame is forwarded by hardware, don't forward in software. */ 48 dsa_default_offload_fwd_mark(skb); 49 50 return skb; 51 } 52 53 static const struct dsa_device_ops xrs700x_netdev_ops = { 54 .name = "xrs700x", 55 .proto = DSA_TAG_PROTO_XRS700X, 56 .xmit = xrs700x_xmit, 57 .rcv = xrs700x_rcv, 58 .needed_tailroom = 1, 59 }; 60 61 MODULE_LICENSE("GPL"); 62 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_XRS700X); 63 64 module_dsa_tag_driver(xrs700x_netdev_ops); 65