154a52823SGeorge McCollister // SPDX-License-Identifier: GPL-2.0+
254a52823SGeorge McCollister /*
354a52823SGeorge McCollister * XRS700x tag format handling
454a52823SGeorge McCollister * Copyright (c) 2008-2009 Marvell Semiconductor
554a52823SGeorge McCollister * Copyright (c) 2020 NovaTech LLC
654a52823SGeorge McCollister */
754a52823SGeorge McCollister
854a52823SGeorge McCollister #include <linux/bitops.h>
954a52823SGeorge McCollister
10*bd954b82SVladimir Oltean #include "tag.h"
1154a52823SGeorge McCollister
1294793a56SVladimir Oltean #define XRS700X_NAME "xrs700x"
1394793a56SVladimir Oltean
xrs700x_xmit(struct sk_buff * skb,struct net_device * dev)1454a52823SGeorge McCollister static struct sk_buff *xrs700x_xmit(struct sk_buff *skb, struct net_device *dev)
1554a52823SGeorge McCollister {
16bd62e6f5SGeorge McCollister struct dsa_port *partner, *dp = dsa_slave_to_port(dev);
1754a52823SGeorge McCollister u8 *trailer;
1854a52823SGeorge McCollister
1954a52823SGeorge McCollister trailer = skb_put(skb, 1);
2054a52823SGeorge McCollister trailer[0] = BIT(dp->index);
2154a52823SGeorge McCollister
22bd62e6f5SGeorge McCollister if (dp->hsr_dev)
23bd62e6f5SGeorge McCollister dsa_hsr_foreach_port(partner, dp->ds, dp->hsr_dev)
24bd62e6f5SGeorge McCollister if (partner != dp)
25bd62e6f5SGeorge McCollister trailer[0] |= BIT(partner->index);
26bd62e6f5SGeorge McCollister
2754a52823SGeorge McCollister return skb;
2854a52823SGeorge McCollister }
2954a52823SGeorge McCollister
xrs700x_rcv(struct sk_buff * skb,struct net_device * dev)3029a097b7SVladimir Oltean static struct sk_buff *xrs700x_rcv(struct sk_buff *skb, struct net_device *dev)
3154a52823SGeorge McCollister {
3254a52823SGeorge McCollister int source_port;
3354a52823SGeorge McCollister u8 *trailer;
3454a52823SGeorge McCollister
3554a52823SGeorge McCollister trailer = skb_tail_pointer(skb) - 1;
3654a52823SGeorge McCollister
3754a52823SGeorge McCollister source_port = ffs((int)trailer[0]) - 1;
3854a52823SGeorge McCollister
3954a52823SGeorge McCollister if (source_port < 0)
4054a52823SGeorge McCollister return NULL;
4154a52823SGeorge McCollister
4254a52823SGeorge McCollister skb->dev = dsa_master_find_slave(dev, 0, source_port);
4354a52823SGeorge McCollister if (!skb->dev)
4454a52823SGeorge McCollister return NULL;
4554a52823SGeorge McCollister
4654a52823SGeorge McCollister if (pskb_trim_rcsum(skb, skb->len - 1))
4754a52823SGeorge McCollister return NULL;
4854a52823SGeorge McCollister
4954a52823SGeorge McCollister /* Frame is forwarded by hardware, don't forward in software. */
50bea79078SVladimir Oltean dsa_default_offload_fwd_mark(skb);
5154a52823SGeorge McCollister
5254a52823SGeorge McCollister return skb;
5354a52823SGeorge McCollister }
5454a52823SGeorge McCollister
5554a52823SGeorge McCollister static const struct dsa_device_ops xrs700x_netdev_ops = {
5694793a56SVladimir Oltean .name = XRS700X_NAME,
5754a52823SGeorge McCollister .proto = DSA_TAG_PROTO_XRS700X,
5854a52823SGeorge McCollister .xmit = xrs700x_xmit,
5954a52823SGeorge McCollister .rcv = xrs700x_rcv,
604e500251SVladimir Oltean .needed_tailroom = 1,
6154a52823SGeorge McCollister };
6254a52823SGeorge McCollister
6354a52823SGeorge McCollister MODULE_LICENSE("GPL");
6494793a56SVladimir Oltean MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_XRS700X, XRS700X_NAME);
6554a52823SGeorge McCollister
6654a52823SGeorge McCollister module_dsa_tag_driver(xrs700x_netdev_ops);
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