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 struct ocelot_8021q_tagger_private { 16 struct ocelot_8021q_tagger_data data; /* Must be first */ 17 struct kthread_worker *xmit_worker; 18 }; 19 20 static struct sk_buff *ocelot_defer_xmit(struct dsa_port *dp, 21 struct sk_buff *skb) 22 { 23 struct ocelot_8021q_tagger_private *priv = dp->ds->tagger_data; 24 struct ocelot_8021q_tagger_data *data = &priv->data; 25 void (*xmit_work_fn)(struct kthread_work *work); 26 struct felix_deferred_xmit_work *xmit_work; 27 struct kthread_worker *xmit_worker; 28 29 xmit_work_fn = data->xmit_work_fn; 30 xmit_worker = priv->xmit_worker; 31 32 if (!xmit_work_fn || !xmit_worker) 33 return NULL; 34 35 /* PTP over IP packets need UDP checksumming. We may have inherited 36 * NETIF_F_HW_CSUM from the DSA master, but these packets are not sent 37 * through the DSA master, so calculate the checksum here. 38 */ 39 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb)) 40 return NULL; 41 42 xmit_work = kzalloc(sizeof(*xmit_work), GFP_ATOMIC); 43 if (!xmit_work) 44 return NULL; 45 46 /* Calls felix_port_deferred_xmit in felix.c */ 47 kthread_init_work(&xmit_work->work, xmit_work_fn); 48 /* Increase refcount so the kfree_skb in dsa_slave_xmit 49 * won't really free the packet. 50 */ 51 xmit_work->dp = dp; 52 xmit_work->skb = skb_get(skb); 53 54 kthread_queue_work(xmit_worker, &xmit_work->work); 55 56 return NULL; 57 } 58 59 static struct sk_buff *ocelot_xmit(struct sk_buff *skb, 60 struct net_device *netdev) 61 { 62 struct dsa_port *dp = dsa_slave_to_port(netdev); 63 u16 queue_mapping = skb_get_queue_mapping(skb); 64 u8 pcp = netdev_txq_to_tc(netdev, queue_mapping); 65 u16 tx_vid = dsa_tag_8021q_standalone_vid(dp); 66 struct ethhdr *hdr = eth_hdr(skb); 67 68 if (ocelot_ptp_rew_op(skb) || is_link_local_ether_addr(hdr->h_dest)) 69 return ocelot_defer_xmit(dp, skb); 70 71 return dsa_8021q_xmit(skb, netdev, ETH_P_8021Q, 72 ((pcp << VLAN_PRIO_SHIFT) | tx_vid)); 73 } 74 75 static struct sk_buff *ocelot_rcv(struct sk_buff *skb, 76 struct net_device *netdev) 77 { 78 int src_port, switch_id; 79 80 dsa_8021q_rcv(skb, &src_port, &switch_id, NULL); 81 82 skb->dev = dsa_master_find_slave(netdev, switch_id, src_port); 83 if (!skb->dev) 84 return NULL; 85 86 dsa_default_offload_fwd_mark(skb); 87 88 return skb; 89 } 90 91 static void ocelot_disconnect(struct dsa_switch *ds) 92 { 93 struct ocelot_8021q_tagger_private *priv = ds->tagger_data; 94 95 kthread_destroy_worker(priv->xmit_worker); 96 kfree(priv); 97 ds->tagger_data = NULL; 98 } 99 100 static int ocelot_connect(struct dsa_switch *ds) 101 { 102 struct ocelot_8021q_tagger_private *priv; 103 int err; 104 105 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 106 if (!priv) 107 return -ENOMEM; 108 109 priv->xmit_worker = kthread_create_worker(0, "felix_xmit"); 110 if (IS_ERR(priv->xmit_worker)) { 111 err = PTR_ERR(priv->xmit_worker); 112 kfree(priv); 113 return err; 114 } 115 116 ds->tagger_data = priv; 117 118 return 0; 119 } 120 121 static const struct dsa_device_ops ocelot_8021q_netdev_ops = { 122 .name = "ocelot-8021q", 123 .proto = DSA_TAG_PROTO_OCELOT_8021Q, 124 .xmit = ocelot_xmit, 125 .rcv = ocelot_rcv, 126 .connect = ocelot_connect, 127 .disconnect = ocelot_disconnect, 128 .needed_headroom = VLAN_HLEN, 129 .promisc_on_master = true, 130 }; 131 132 MODULE_LICENSE("GPL v2"); 133 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT_8021Q); 134 135 module_dsa_tag_driver(ocelot_8021q_netdev_ops); 136