Re: [patch net-next 02/19] net: bridge: Add support for offloading port attributes

On 06/05/2017 04:29 PM, Nikolay Aleksandrov wrote:

On 05/06/17 12:20, Jiri Pirko wrote:

quoted

From: Arkadi Sharshevsky <redacted>

Currently the flood, learning and learning_sync port attributes are
offloaded by setting the SELF flag. Add support for offloading the
flood and learning attribute through the bridge code. In case of
setting an unsupported flag on a offloded port the operation will
fail.

The learning_sync attribute doesn't have any software representation
and cannot be offloaded through the bridge code.

Signed-off-by: Arkadi Sharshevsky <redacted>
Reviewed-by: Ido Schimmel <redacted>
Signed-off-by: Jiri Pirko <redacted>
---
 net/bridge/br_netlink.c | 112 +++++++++++++++++++++++++++++++++++++++---------
 net/bridge/br_private.h |   4 ++
 2 files changed, 96 insertions(+), 20 deletions(-)

Hi Arkadi,
A few comments below

Hi Nikolay,
Thank you very much for the review, will fix.

quoted

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 1e63ec4..1afafb7 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c

@@ -17,6 +17,7 @@
 #include <net/net_namespace.h>
 #include <net/sock.h>
 #include <uapi/linux/if_bridge.h>
+#include <net/switchdev.h>
 
 #include "br_private.h"
 #include "br_private_stp.h"

@@ -662,16 +663,52 @@ static int br_set_port_state(struct net_bridge_port *p, u8 state)
 }
 
 /* Set/clear or port flags based on attribute */
-static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
-			   int attrtype, unsigned long mask)
+static int br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
+			    int attrtype, unsigned long mask)
 {
-	if (tb[attrtype]) {
-		u8 flag = nla_get_u8(tb[attrtype]);
-		if (flag)
-			p->flags |= mask;
-		else
-			p->flags &= ~mask;
+	struct switchdev_attr attr = {
+		.orig_dev = p->dev,
+		.id = SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS_SUPPORT,
+	};
+	unsigned long flags;
+	int err;
+
+	if (!tb[attrtype])
+		return 0;
+
+	if (nla_get_u8(tb[attrtype]))
+		flags = p->flags | mask;
+	else
+		flags = p->flags & ~mask;
+
+	if (mask & ~BR_PORT_FLAGS_HW_OFFLOAD)
+		goto out;
+
+	err = switchdev_port_attr_get(p->dev, &attr);
+	if (err == -EOPNOTSUPP)
+		goto out;
+	if (err)
+		return err;
+
+	/* Check if specific bridge flag attribute offload is supported */
+	if (!(attr.u.brport_flags_support & mask)) {
+		br_warn(p->br, "bridge flag offload is not supported %u(%s)\n",
+			(unsigned int)p->port_no, p->dev->name);
+		return -EOPNOTSUPP;
+	}
+
+	attr.id = SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS;
+	attr.flags = SWITCHDEV_F_DEFER;
+	attr.u.brport_flags = flags;
+	err = switchdev_port_attr_set(p->dev, &attr);
+	if (err) {
+		br_warn(p->br, "error setting offload FLAG on port %u(%s)\n",

Why all caps (FLAG) ?

quoted

+			(unsigned int)p->port_no, p->dev->name);
+		return err;
 	}

I think all of this switchdev-specific code should be contained into br_switchdev.c and
exported via some function. Anyone changing only the bridge can easily get confused.

quoted

+out:
+	p->flags = flags;
+	return 0;
 }
 
 /* Process bridge protocol info on port */

@@ -681,20 +718,55 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 	bool br_vlan_tunnel_old = false;
 	int err;
 
-	br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
-	br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
-	br_set_port_flag(p, tb, IFLA_BRPORT_FAST_LEAVE, BR_MULTICAST_FAST_LEAVE);
-	br_set_port_flag(p, tb, IFLA_BRPORT_PROTECT, BR_ROOT_BLOCK);
-	br_set_port_flag(p, tb, IFLA_BRPORT_LEARNING, BR_LEARNING);
-	br_set_port_flag(p, tb, IFLA_BRPORT_UNICAST_FLOOD, BR_FLOOD);
-	br_set_port_flag(p, tb, IFLA_BRPORT_MCAST_FLOOD, BR_MCAST_FLOOD);
-	br_set_port_flag(p, tb, IFLA_BRPORT_MCAST_TO_UCAST, BR_MULTICAST_TO_UNICAST);
-	br_set_port_flag(p, tb, IFLA_BRPORT_BCAST_FLOOD, BR_BCAST_FLOOD);
-	br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP, BR_PROXYARP);
-	br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP_WIFI, BR_PROXYARP_WIFI);
+	err = br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
+	if (err)
+		return err;
+
+	err = br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
+	if (err)
+		return err;
+
+	err = br_set_port_flag(p, tb, IFLA_BRPORT_FAST_LEAVE, BR_MULTICAST_FAST_LEAVE);
+	if (err)
+		return err;
+
+	err = br_set_port_flag(p, tb, IFLA_BRPORT_PROTECT, BR_ROOT_BLOCK);
+	if (err)
+		return err;
+
+	err = br_set_port_flag(p, tb, IFLA_BRPORT_LEARNING, BR_LEARNING);
+	if (err)
+		return err;
+
+	err = br_set_port_flag(p, tb, IFLA_BRPORT_UNICAST_FLOOD, BR_FLOOD);
+	if (err)
+		return err;
+
+	err = br_set_port_flag(p, tb, IFLA_BRPORT_MCAST_FLOOD, BR_MCAST_FLOOD);
+	if (err)
+		return err;
+
+	err = br_set_port_flag(p, tb, IFLA_BRPORT_MCAST_TO_UCAST, BR_MULTICAST_TO_UNICAST);
+	if (err)
+		return err;
+
+	err = br_set_port_flag(p, tb, IFLA_BRPORT_BCAST_FLOOD, BR_BCAST_FLOOD);
+	if (err)
+		return err;
+
+	err = br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP, BR_PROXYARP);
+	if (err)
+		return err;
+
+	err = br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP_WIFI, BR_PROXYARP_WIFI);
+	if (err)
+		return err;
 
 	br_vlan_tunnel_old = (p->flags & BR_VLAN_TUNNEL) ? true : false;
-	br_set_port_flag(p, tb, IFLA_BRPORT_VLAN_TUNNEL, BR_VLAN_TUNNEL);
+	err = br_set_port_flag(p, tb, IFLA_BRPORT_VLAN_TUNNEL, BR_VLAN_TUNNEL);
+	if (err)
+		return err;
+
 	if (br_vlan_tunnel_old && !(p->flags & BR_VLAN_TUNNEL))
 		nbp_vlan_tunnel_info_flush(p);
 

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 2062692..5dc30ed 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h

@@ -42,6 +42,10 @@
 /* Path to usermode spanning tree program */
 #define BR_STP_PROG	"/sbin/bridge-stp"
 
+/* Flags that can be offloaded to hardware */
+#define BR_PORT_FLAGS_HW_OFFLOAD (BR_LEARNING | BR_FLOOD | \
+				  BR_MCAST_FLOOD | BR_BCAST_FLOOD)
+
 typedef struct bridge_id bridge_id;
 typedef struct mac_addr mac_addr;
 typedef __u16 port_id;