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From: Vladimir Oltean <vladimir.oltean@nxp.com>
To: netdev@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>,
	"David S. Miller" <davem@davemloft.net>
Cc: Andrew Lunn <andrew@lunn.ch>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Vivien Didelot <vivien.didelot@gmail.com>,
	Jiri Pirko <jiri@resnulli.us>, Ido Schimmel <idosch@idosch.org>,
	Tobias Waldekranz <tobias@waldekranz.com>,
	Roopa Prabhu <roopa@nvidia.com>,
	Nikolay Aleksandrov <nikolay@nvidia.com>,
	Stephen Hemminger <stephen@networkplumber.org>,
	bridge@lists.linux-foundation.org,
	Grygorii Strashko <grygorii.strashko@ti.com>,
	Marek Behun <kabel@blackhole.sk>,
	DENG Qingfang <dqfext@gmail.com>
Subject: [PATCH v4 net-next 15/15] net: dsa: tag_dsa: offload the bridge forwarding process
Date: Mon, 19 Jul 2021 00:44:34 +0300	[thread overview]
Message-ID: <20210718214434.3938850-16-vladimir.oltean@nxp.com> (raw)
In-Reply-To: <20210718214434.3938850-1-vladimir.oltean@nxp.com>

From: Tobias Waldekranz <tobias@waldekranz.com>

Allow the DSA tagger to generate FORWARD frames for offloaded skbs
sent from a bridge that we offload, allowing the switch to handle any
frame replication that may be required. This also means that source
address learning takes place on packets sent from the CPU, meaning
that return traffic no longer needs to be flooded as unknown unicast.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
v1->v2:
- use the VLAN from the packet when the bridge is VLAN-aware, and the
  PVID of the bridge when VLAN-unaware, instead of the PVID of the
  egress port as the code was originally written
- retrieve the sb_dev based on the TX queue mapping of the skb instead
  of based on the DSA_SKB_CB() populated in the ndo_select_queue()
  method, because DSA does not have ownership of the skb there yet
v2->v3:
- use skb->offload_fwd_mark instead of dsa_slave_get_sb_dev() and TX
  queue mappings
- drop the "bool bridge_fwd_offload"
v3->v4:
- none

 net/dsa/tag_dsa.c | 52 +++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 44 insertions(+), 8 deletions(-)

diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c
index a822355afc90..0f258218c8cf 100644
--- a/net/dsa/tag_dsa.c
+++ b/net/dsa/tag_dsa.c
@@ -126,7 +126,42 @@ static struct sk_buff *dsa_xmit_ll(struct sk_buff *skb, struct net_device *dev,
 				   u8 extra)
 {
 	struct dsa_port *dp = dsa_slave_to_port(dev);
+	u8 tag_dev, tag_port;
+	enum dsa_cmd cmd;
 	u8 *dsa_header;
+	u16 pvid = 0;
+	int err;
+
+	if (skb->offload_fwd_mark) {
+		struct dsa_switch_tree *dst = dp->ds->dst;
+		struct net_device *br = dp->bridge_dev;
+
+		cmd = DSA_CMD_FORWARD;
+
+		/* When offloading forwarding for a bridge, inject FORWARD
+		 * packets on behalf of a virtual switch device with an index
+		 * past the physical switches.
+		 */
+		tag_dev = dst->last_switch + 1 + dp->bridge_num;
+		tag_port = 0;
+
+		/* If we are offloading forwarding for a VLAN-unaware bridge,
+		 * inject packets to hardware using the bridge's pvid, since
+		 * that's where the packets ingressed from.
+		 */
+		if (!br_vlan_enabled(br)) {
+			/* Safe because __dev_queue_xmit() runs under
+			 * rcu_read_lock_bh()
+			 */
+			err = br_vlan_get_pvid_rcu(br, &pvid);
+			if (err)
+				return NULL;
+		}
+	} else {
+		cmd = DSA_CMD_FROM_CPU;
+		tag_dev = dp->ds->index;
+		tag_port = dp->index;
+	}
 
 	if (skb->protocol == htons(ETH_P_8021Q)) {
 		if (extra) {
@@ -134,10 +169,10 @@ static struct sk_buff *dsa_xmit_ll(struct sk_buff *skb, struct net_device *dev,
 			memmove(skb->data, skb->data + extra, 2 * ETH_ALEN);
 		}
 
-		/* Construct tagged FROM_CPU DSA tag from 802.1Q tag. */
+		/* Construct tagged DSA tag from 802.1Q tag. */
 		dsa_header = skb->data + 2 * ETH_ALEN + extra;
-		dsa_header[0] = (DSA_CMD_FROM_CPU << 6) | 0x20 | dp->ds->index;
-		dsa_header[1] = dp->index << 3;
+		dsa_header[0] = (cmd << 6) | 0x20 | tag_dev;
+		dsa_header[1] = tag_port << 3;
 
 		/* Move CFI field from byte 2 to byte 1. */
 		if (dsa_header[2] & 0x10) {
@@ -148,12 +183,13 @@ static struct sk_buff *dsa_xmit_ll(struct sk_buff *skb, struct net_device *dev,
 		skb_push(skb, DSA_HLEN + extra);
 		memmove(skb->data, skb->data + DSA_HLEN + extra, 2 * ETH_ALEN);
 
-		/* Construct untagged FROM_CPU DSA tag. */
+		/* Construct untagged DSA tag. */
 		dsa_header = skb->data + 2 * ETH_ALEN + extra;
-		dsa_header[0] = (DSA_CMD_FROM_CPU << 6) | dp->ds->index;
-		dsa_header[1] = dp->index << 3;
-		dsa_header[2] = 0x00;
-		dsa_header[3] = 0x00;
+
+		dsa_header[0] = (cmd << 6) | tag_dev;
+		dsa_header[1] = tag_port << 3;
+		dsa_header[2] = pvid >> 8;
+		dsa_header[3] = pvid & 0xff;
 	}
 
 	return skb;
-- 
2.25.1


  parent reply	other threads:[~2021-07-18 21:46 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-18 21:44 [PATCH v4 net-next 00/15] Allow forwarding for the software bridge data path to be offloaded to capable devices Vladimir Oltean
2021-07-18 21:44 ` [PATCH v4 net-next 01/15] net: dpaa2-switch: use extack in dpaa2_switch_port_bridge_join Vladimir Oltean
2021-07-19  9:17   ` Ioana Ciornei
2021-07-18 21:44 ` [PATCH v4 net-next 02/15] net: dpaa2-switch: refactor prechangeupper sanity checks Vladimir Oltean
2021-07-19  9:18   ` Ioana Ciornei
2021-07-18 21:44 ` [PATCH v4 net-next 03/15] mlxsw: spectrum: " Vladimir Oltean
2021-07-18 21:44 ` [PATCH v4 net-next 04/15] mlxsw: spectrum: refactor leaving an 8021q upper that is a bridge port Vladimir Oltean
2021-07-19  2:16   ` Florian Fainelli
2021-07-18 21:44 ` [PATCH v4 net-next 05/15] net: marvell: prestera: refactor prechangeupper sanity checks Vladimir Oltean
2021-07-19  2:20   ` Florian Fainelli
2021-07-18 21:44 ` [PATCH v4 net-next 06/15] net: switchdev: guard drivers against multiple obj replays on same bridge port Vladimir Oltean
2021-07-19  2:17   ` Florian Fainelli
2021-07-18 21:44 ` [PATCH v4 net-next 07/15] net: bridge: disambiguate offload_fwd_mark Vladimir Oltean
2021-07-19  2:26   ` Florian Fainelli
2021-07-18 21:44 ` [PATCH v4 net-next 08/15] net: bridge: switchdev: recycle unused hwdoms Vladimir Oltean
2021-07-18 21:44 ` [PATCH v4 net-next 09/15] net: bridge: switchdev: let drivers inform which bridge ports are offloaded Vladimir Oltean
2021-07-19  9:23   ` Ioana Ciornei
2021-07-20  7:53   ` Horatiu Vultur
2021-07-20  8:45     ` Vladimir Oltean
2021-07-18 21:44 ` [PATCH v4 net-next 10/15] net: bridge: switchdev object replay helpers for everybody Vladimir Oltean
2021-07-19  8:19   ` Vladimir Oltean
2021-07-19  9:26   ` Ioana Ciornei
2021-07-18 21:44 ` [PATCH v4 net-next 11/15] net: bridge: switchdev: allow the TX data plane forwarding to be offloaded Vladimir Oltean
2021-07-19  2:43   ` Florian Fainelli
2021-07-19  7:22   ` Vladimir Oltean
2021-07-18 21:44 ` [PATCH v4 net-next 12/15] net: dsa: track the number of switches in a tree Vladimir Oltean
2021-07-19  2:54   ` Florian Fainelli
2021-07-18 21:44 ` [PATCH v4 net-next 13/15] net: dsa: add support for bridge TX forwarding offload Vladimir Oltean
2021-07-19  2:51   ` Florian Fainelli
2021-07-18 21:44 ` [PATCH v4 net-next 14/15] net: dsa: mv88e6xxx: map virtual bridges with forwarding offload in the PVT Vladimir Oltean
2021-07-19  2:52   ` Florian Fainelli
2021-07-18 21:44 ` Vladimir Oltean [this message]
2021-07-19  2:47   ` [PATCH v4 net-next 15/15] net: dsa: tag_dsa: offload the bridge forwarding process Florian Fainelli
2021-07-19  7:41     ` Vladimir Oltean
2021-07-20 11:24 ` [PATCH v4 net-next 00/15] Allow forwarding for the software bridge data path to be offloaded to capable devices Ido Schimmel
2021-07-20 13:20   ` Vladimir Oltean
2021-07-20 13:51     ` Ido Schimmel

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