cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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tag_xrs700x.c (1372B)

      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
     12static 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
     28static 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
     53static 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
     61MODULE_LICENSE("GPL");
     62MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_XRS700X);
     63
     64module_dsa_tag_driver(xrs700x_netdev_ops);