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authorVladimir Oltean <vladimir.oltean@nxp.com>2021-07-22 18:55:40 +0300
committerDavid S. Miller <davem@davemloft.net>2021-07-23 18:32:37 +0300
commit123abc06e74f49d9b173a93cb2b797fb85f50ba3 (patch)
tree2811a4e0668e612d7fa911ce5c44aa3c13dd4634 /net/dsa/dsa_priv.h
parent5b22d3669f2fa6e762c5302fc4b6051a92b81617 (diff)
downloadlinux-123abc06e74f49d9b173a93cb2b797fb85f50ba3.tar.xz
net: dsa: add support for bridge TX forwarding offload
For a DSA switch, to offload the forwarding process of a bridge device means to send the packets coming from the software bridge as data plane packets. This is contrary to everything that DSA has done so far, because the current taggers only know to send control packets (ones that target a specific destination port), whereas data plane packets are supposed to be forwarded according to the FDB lookup, much like packets ingressing on any regular ingress port. If the FDB lookup process returns multiple destination ports (flooding, multicast), then replication is also handled by the switch hardware - the bridge only sends a single packet and avoids the skb_clone(). DSA keeps for each bridge port a zero-based index (the number of the bridge). Multiple ports performing TX forwarding offload to the same bridge have the same dp->bridge_num value, and ports not offloading the TX data plane of a bridge have dp->bridge_num = -1. The tagger can check if the packet that is being transmitted on has skb->offload_fwd_mark = true or not. If it does, it can be sure that the packet belongs to the data plane of a bridge, further information about which can be obtained based on dp->bridge_dev and dp->bridge_num. It can then compose a DSA tag for injecting a data plane packet into that bridge number. For the switch driver side, we offer two new dsa_switch_ops methods, called .port_bridge_fwd_offload_{add,del}, which are modeled after .port_bridge_{join,leave}. These methods are provided in case the driver needs to configure the hardware to treat packets coming from that bridge software interface as data plane packets. The switchdev <-> bridge interaction happens during the netdev_master_upper_dev_link() call, so to switch drivers, the effect is that the .port_bridge_fwd_offload_add() method is called immediately after .port_bridge_join(). If the bridge number exceeds the number of bridges for which the switch driver can offload the TX data plane (and this includes the case where the driver can offload none), DSA falls back to simply returning tx_fwd_offload = false in the switchdev_bridge_port_offload() call. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dsa/dsa_priv.h')
-rw-r--r--net/dsa/dsa_priv.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 78c70f5bdab5..b1d9aa4d313c 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -14,6 +14,8 @@
#include <net/dsa.h>
#include <net/gro_cells.h>
+#define DSA_MAX_NUM_OFFLOADING_BRIDGES BITS_PER_LONG
+
enum {
DSA_NOTIFIER_AGEING_TIME,
DSA_NOTIFIER_BRIDGE_JOIN,