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Diffstat (limited to 'net/dsa/tag_sja1105.c')
-rw-r--r--net/dsa/tag_sja1105.c131
1 files changed, 131 insertions, 0 deletions
diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c
new file mode 100644
index 000000000000..969402c7dbf1
--- /dev/null
+++ b/net/dsa/tag_sja1105.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com>
+ */
+#include <linux/if_vlan.h>
+#include <linux/dsa/sja1105.h>
+#include <linux/dsa/8021q.h>
+#include <linux/packing.h>
+#include "dsa_priv.h"
+
+/* Similar to is_link_local_ether_addr(hdr->h_dest) but also covers PTP */
+static inline bool sja1105_is_link_local(const struct sk_buff *skb)
+{
+ const struct ethhdr *hdr = eth_hdr(skb);
+ u64 dmac = ether_addr_to_u64(hdr->h_dest);
+
+ if ((dmac & SJA1105_LINKLOCAL_FILTER_A_MASK) ==
+ SJA1105_LINKLOCAL_FILTER_A)
+ return true;
+ if ((dmac & SJA1105_LINKLOCAL_FILTER_B_MASK) ==
+ SJA1105_LINKLOCAL_FILTER_B)
+ return true;
+ return false;
+}
+
+/* This is the first time the tagger sees the frame on RX.
+ * Figure out if we can decode it, and if we can, annotate skb->cb with how we
+ * plan to do that, so we don't need to check again in the rcv function.
+ */
+static bool sja1105_filter(const struct sk_buff *skb, struct net_device *dev)
+{
+ if (sja1105_is_link_local(skb)) {
+ SJA1105_SKB_CB(skb)->type = SJA1105_FRAME_TYPE_LINK_LOCAL;
+ return true;
+ }
+ if (!dsa_port_is_vlan_filtering(dev->dsa_ptr)) {
+ SJA1105_SKB_CB(skb)->type = SJA1105_FRAME_TYPE_NORMAL;
+ return true;
+ }
+ return false;
+}
+
+static struct sk_buff *sja1105_xmit(struct sk_buff *skb,
+ struct net_device *netdev)
+{
+ struct dsa_port *dp = dsa_slave_to_port(netdev);
+ struct dsa_switch *ds = dp->ds;
+ u16 tx_vid = dsa_8021q_tx_vid(ds, dp->index);
+ u8 pcp = skb->priority;
+
+ /* Transmitting management traffic does not rely upon switch tagging,
+ * but instead SPI-installed management routes. Part 2 of this
+ * is the .port_deferred_xmit driver callback.
+ */
+ if (unlikely(sja1105_is_link_local(skb)))
+ return dsa_defer_xmit(skb, netdev);
+
+ /* If we are under a vlan_filtering bridge, IP termination on
+ * switch ports based on 802.1Q tags is simply too brittle to
+ * be passable. So just defer to the dsa_slave_notag_xmit
+ * implementation.
+ */
+ if (dsa_port_is_vlan_filtering(dp))
+ return skb;
+
+ return dsa_8021q_xmit(skb, netdev, ETH_P_SJA1105,
+ ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
+}
+
+static struct sk_buff *sja1105_rcv(struct sk_buff *skb,
+ struct net_device *netdev,
+ struct packet_type *pt)
+{
+ struct ethhdr *hdr = eth_hdr(skb);
+ u64 source_port, switch_id;
+ struct sk_buff *nskb;
+ u16 tpid, vid, tci;
+ bool is_tagged;
+
+ nskb = dsa_8021q_rcv(skb, netdev, pt, &tpid, &tci);
+ is_tagged = (nskb && tpid == ETH_P_SJA1105);
+
+ skb->priority = (tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
+ vid = tci & VLAN_VID_MASK;
+
+ skb->offload_fwd_mark = 1;
+
+ if (SJA1105_SKB_CB(skb)->type == SJA1105_FRAME_TYPE_LINK_LOCAL) {
+ /* Management traffic path. Switch embeds the switch ID and
+ * port ID into bytes of the destination MAC, courtesy of
+ * the incl_srcpt options.
+ */
+ source_port = hdr->h_dest[3];
+ switch_id = hdr->h_dest[4];
+ /* Clear the DMAC bytes that were mangled by the switch */
+ hdr->h_dest[3] = 0;
+ hdr->h_dest[4] = 0;
+ } else {
+ /* Normal traffic path. */
+ source_port = dsa_8021q_rx_source_port(vid);
+ switch_id = dsa_8021q_rx_switch_id(vid);
+ }
+
+ skb->dev = dsa_master_find_slave(netdev, switch_id, source_port);
+ if (!skb->dev) {
+ netdev_warn(netdev, "Couldn't decode source port\n");
+ return NULL;
+ }
+
+ /* Delete/overwrite fake VLAN header, DSA expects to not find
+ * it there, see dsa_switch_rcv: skb_push(skb, ETH_HLEN).
+ */
+ if (is_tagged)
+ memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - VLAN_HLEN,
+ ETH_HLEN - VLAN_HLEN);
+
+ return skb;
+}
+
+static struct dsa_device_ops sja1105_netdev_ops = {
+ .name = "sja1105",
+ .proto = DSA_TAG_PROTO_SJA1105,
+ .xmit = sja1105_xmit,
+ .rcv = sja1105_rcv,
+ .filter = sja1105_filter,
+ .overhead = VLAN_HLEN,
+};
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SJA1105);
+
+module_dsa_tag_driver(sja1105_netdev_ops);