net/dsa/tag_ocelot_8021q.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright 2020-2021 NXP
   3  *
   4  * An implementation of the software-defined tag_8021q.c tagger format, which
   5  * also preserves full functionality under a vlan_filtering bridge. It does
   6  * this by using the TCAM engines for:
   7  * - pushing the RX VLAN as a second, outer tag, on egress towards the CPU port
   8  * - redirecting towards the correct front port based on TX VLAN and popping
   9  *   that on egress
  10  */
  11 #include <linux/dsa/8021q.h>
  12 #include <linux/dsa/ocelot.h>
  13 #include "dsa_priv.h"
  14
  15 static struct sk_buff *ocelot_defer_xmit(struct dsa_port *dp,
  16                                          struct sk_buff *skb)
  17 {
  18         struct felix_deferred_xmit_work *xmit_work;
  19         struct felix_port *felix_port = dp->priv;
  20
  21         xmit_work = kzalloc(sizeof(*xmit_work), GFP_ATOMIC);
  22         if (!xmit_work)
  23                 return NULL;
  24
  25         /* Calls felix_port_deferred_xmit in felix.c */
  26         kthread_init_work(&xmit_work->work, felix_port->xmit_work_fn);
  27         /* Increase refcount so the kfree_skb in dsa_slave_xmit
  28          * won't really free the packet.
  29          */
  30         xmit_work->dp = dp;
  31         xmit_work->skb = skb_get(skb);
  32
  33         kthread_queue_work(felix_port->xmit_worker, &xmit_work->work);
  34
  35         return NULL;
  36 }
  37
  38 static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
  39                                    struct net_device *netdev)
  40 {
  41         struct dsa_port *dp = dsa_slave_to_port(netdev);
  42         u16 tx_vid = dsa_8021q_tx_vid(dp->ds, dp->index);
  43         u16 queue_mapping = skb_get_queue_mapping(skb);
  44         u8 pcp = netdev_txq_to_tc(netdev, queue_mapping);
  45         struct ethhdr *hdr = eth_hdr(skb);
  46
  47         if (ocelot_ptp_rew_op(skb) || is_link_local_ether_addr(hdr->h_dest))
  48                 return ocelot_defer_xmit(dp, skb);
  49
  50         return dsa_8021q_xmit(skb, netdev, ETH_P_8021Q,
  51                               ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
  52 }
  53
  54 static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
  55                                   struct net_device *netdev)
  56 {
  57         int src_port, switch_id;
  58
  59         dsa_8021q_rcv(skb, &src_port, &switch_id);
  60
  61         skb->dev = dsa_master_find_slave(netdev, switch_id, src_port);
  62         if (!skb->dev)
  63                 return NULL;
  64
  65         dsa_default_offload_fwd_mark(skb);
  66
  67         return skb;
  68 }
  69
  70 static const struct dsa_device_ops ocelot_8021q_netdev_ops = {
  71         .name                   = "ocelot-8021q",
  72         .proto                  = DSA_TAG_PROTO_OCELOT_8021Q,
  73         .xmit                   = ocelot_xmit,
  74         .rcv                    = ocelot_rcv,
  75         .needed_headroom        = VLAN_HLEN,
  76         .promisc_on_master      = true,
  77 };
  78
  79 MODULE_LICENSE("GPL v2");
  80 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT_8021Q);
  81
  82 module_dsa_tag_driver(ocelot_8021q_netdev_ops);