Linux Ethernet Bridging - May 2018 - [Bridge] [PATCH net-next v3 2/7] mlxsw: spectrum_switchdev: Ignore bridge VLAN events

In commit 946a11e7408e ("mlxsw: spectrum_span: Allow bridge for gretap
mirror"), mlxsw got support for offloading mirror-to-gretap such that
the underlay packet path involves a bridge. In that case, the offload is
also influenced by PVID setting of said bridge. However, changes to VLAN
configuration of the bridge itself do not generate switchdev
notifications, so there's no mechanism to prod mlxsw to update the
offload when these settings change.

In this patchset, the problem is resolved by distributing the switchdev
notification SWITCHDEV_OBJ_ID_PORT_VLAN also for configuration changes
on bridge VLANs. Since stacked devices distribute the notification to
lower devices, such event eventually reaches the driver, which can
determine whether it's a bridge or port VLAN by inspecting orig_dev.

To keep things consistent, the newly-distributed notifications observe
the same protocol as the existing ones: dual prepare/commit, with
-EOPNOTSUPP indicating lack of support, even though there's currently
nothing to prepare for and nothing to support. Correspondingly, all
switchdev drivers have been updated to return -EOPNOTSUPP for bridge
VLAN notifications.

In patch #1, the code to send notifications for adding and deleting is
factored out into two named functions.

In patches #2-#5, respectively for mlxsw, rocker, DSA and DPAA2 ethsw,
the new notifications (which are not enabled yet) are ignored to
maintain the current behavior.

In patch #6, the notification is actually enabled.

In patch #7, mlxsw is changed to update offloads of mirror-to-gre also
for bridge-related notifications.

Changes from v2 to v3:

- Add a fallback definition for br_switchdev_port_obj_add() and
  br_switchdev_port_obj_del() when !CONFIG_NET_SWITCHDEV.

Changes from v1 to v2:

- Rename br_switchdev_port_obj_add() and br_switchdev_port_obj_del() to
  br_switchdev_port_vlan_add() and br_switchdev_port_vlan_del(), and
  move from br_vlan.c to br_switchdev.c.

Petr Machata (7):
  net: bridge: Extract boilerplate around switchdev_port_obj_*()
  mlxsw: spectrum_switchdev: Ignore bridge VLAN events
  rocker: rocker_main: Ignore bridge VLAN events
  dsa: port: Ignore bridge VLAN events
  staging: fsl-dpaa2: ethsw: Ignore bridge VLAN events
  net: bridge: Notify about bridge VLANs
  mlxsw: spectrum_switchdev: Schedule respin during trans prepare

 .../ethernet/mellanox/mlxsw/spectrum_switchdev.c   |  8 +++-
 drivers/net/ethernet/rocker/rocker_main.c          |  6 +++
 drivers/staging/fsl-dpaa2/ethsw/ethsw.c            |  6 +++
 net/bridge/br_private.h                            | 13 +++++++
 net/bridge/br_switchdev.c                          | 25 ++++++++++++
 net/bridge/br_vlan.c                               | 45 +++++++++-------------
 net/dsa/port.c                                     |  6 +++
 7 files changed, 81 insertions(+), 28 deletions(-)

-- 
2.4.11

A call to switchdev_port_obj_add() or switchdev_port_obj_del() involves
initializing a struct switchdev_obj_port_vlan, a piece of code that
repeats on each call site almost verbatim. While in the current codebase
there is just one duplicated add call, the follow-up patches add more of
both add and del calls.

Thus to remove the duplication, extract the repetition into named
functions and reuse.

Signed-off-by: Petr Machata <petrm at mellanox.com>
---
 net/bridge/br_private.h   | 13 +++++++++++++
 net/bridge/br_switchdev.c | 25 +++++++++++++++++++++++++
 net/bridge/br_vlan.c      | 31 ++++---------------------------
 3 files changed, 42 insertions(+), 27 deletions(-)

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 11520ed..5216a52 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1139,6 +1139,8 @@ int br_switchdev_set_port_flag(struct net_bridge_port *p,
 			       unsigned long mask);
 void br_switchdev_fdb_notify(const struct net_bridge_fdb_entry *fdb,
 			     int type);
+int br_switchdev_port_vlan_add(struct net_device *dev, u16 vid, u16 flags);
+int br_switchdev_port_vlan_del(struct net_device *dev, u16 vid);
 
 static inline void br_switchdev_frame_unmark(struct sk_buff *skb)
 {
@@ -1168,6 +1170,17 @@ static inline int br_switchdev_set_port_flag(struct
net_bridge_port *p,
 	return 0;
 }
 
+static inline int br_switchdev_port_vlan_add(struct net_device *dev,
+					     u16 vid, u16 flags)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int br_switchdev_port_vlan_del(struct net_device *dev, u16 vid)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline void
 br_switchdev_fdb_notify(const struct net_bridge_fdb_entry *fdb, int type)
 {
diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c
index 35474d4..d77f807 100644
--- a/net/bridge/br_switchdev.c
+++ b/net/bridge/br_switchdev.c
@@ -136,3 +136,28 @@ br_switchdev_fdb_notify(const struct net_bridge_fdb_entry
*fdb, int type)
 		break;
 	}
 }
+
+int br_switchdev_port_vlan_add(struct net_device *dev, u16 vid, u16 flags)
+{
+	struct switchdev_obj_port_vlan v = {
+		.obj.orig_dev = dev,
+		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
+		.flags = flags,
+		.vid_begin = vid,
+		.vid_end = vid,
+	};
+
+	return switchdev_port_obj_add(dev, &v.obj);
+}
+
+int br_switchdev_port_vlan_del(struct net_device *dev, u16 vid)
+{
+	struct switchdev_obj_port_vlan v = {
+		.obj.orig_dev = dev,
+		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
+		.vid_begin = vid,
+		.vid_end = vid,
+	};
+
+	return switchdev_port_obj_del(dev, &v.obj);
+}
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index dc832c09..8ad5756 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -82,19 +82,10 @@ static bool __vlan_add_flags(struct net_bridge_vlan *v, u16
flags)
 static int __vlan_vid_add(struct net_device *dev, struct net_bridge *br,
 			  u16 vid, u16 flags)
 {
-	struct switchdev_obj_port_vlan v = {
-		.obj.orig_dev = dev,
-		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
-		.flags = flags,
-		.vid_begin = vid,
-		.vid_end = vid,
-	};
-	int err;
-
 	/* Try switchdev op first. In case it is not supported, fallback to
 	 * 8021q add.
 	 */
-	err = switchdev_port_obj_add(dev, &v.obj);
+	int err = br_switchdev_port_vlan_add(dev, vid, flags);
 	if (err == -EOPNOTSUPP)
 		return vlan_vid_add(dev, br->vlan_proto, vid);
 	return err;
@@ -130,18 +121,11 @@ static void __vlan_del_list(struct net_bridge_vlan *v)
 static int __vlan_vid_del(struct net_device *dev, struct net_bridge *br,
 			  u16 vid)
 {
-	struct switchdev_obj_port_vlan v = {
-		.obj.orig_dev = dev,
-		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
-		.vid_begin = vid,
-		.vid_end = vid,
-	};
-	int err;
-
 	/* Try switchdev op first. In case it is not supported, fallback to
 	 * 8021q del.
 	 */
-	err = switchdev_port_obj_del(dev, &v.obj);
+	int err = br_switchdev_port_vlan_del(dev, vid);
+
 	if (err == -EOPNOTSUPP) {
 		vlan_vid_del(dev, br->vlan_proto, vid);
 		return 0;
@@ -1053,13 +1037,6 @@ int nbp_vlan_init(struct net_bridge_port *p)
 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags,
 		 bool *changed)
 {
-	struct switchdev_obj_port_vlan v = {
-		.obj.orig_dev = port->dev,
-		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
-		.flags = flags,
-		.vid_begin = vid,
-		.vid_end = vid,
-	};
 	struct net_bridge_vlan *vlan;
 	int ret;
 
@@ -1069,7 +1046,7 @@ int nbp_vlan_add(struct net_bridge_port *port, u16 vid,
u16 flags,
 	vlan = br_vlan_find(nbp_vlan_group(port), vid);
 	if (vlan) {
 		/* Pass the flags to the hardware bridge */
-		ret = switchdev_port_obj_add(port->dev, &v.obj);
+		ret = br_switchdev_port_vlan_add(port->dev, vid, flags);
 		if (ret && ret != -EOPNOTSUPP)
 			return ret;
 		*changed = __vlan_add_flags(vlan, flags);
-- 
2.4.11

Ignore VLAN events where the orig_dev is the bridge device itself.

Signed-off-by: Petr Machata <petrm at mellanox.com>
Reviewed-by: Ido Schimmel <idosch at mellanox.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
index 8c9cf8e..cbc8fab 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
@@ -1144,6 +1144,9 @@ static int mlxsw_sp_port_vlans_add(struct mlxsw_sp_port
*mlxsw_sp_port,
 	struct mlxsw_sp_bridge_port *bridge_port;
 	u16 vid;
 
+	if (netif_is_bridge_master(orig_dev))
+		return -EOPNOTSUPP;
+
 	if (switchdev_trans_ph_prepare(trans))
 		return 0;
 
@@ -1741,6 +1744,9 @@ static int mlxsw_sp_port_vlans_del(struct mlxsw_sp_port
*mlxsw_sp_port,
 	struct mlxsw_sp_bridge_port *bridge_port;
 	u16 vid;
 
+	if (netif_is_bridge_master(orig_dev))
+		return -EOPNOTSUPP;
+
 	bridge_port = mlxsw_sp_bridge_port_find(mlxsw_sp->bridge, orig_dev);
 	if (WARN_ON(!bridge_port))
 		return -EINVAL;
-- 
2.4.11

Ignore VLAN events where the orig_dev is the bridge device itself.

Signed-off-by: Petr Machata <petrm at mellanox.com>
---
 drivers/net/ethernet/rocker/rocker_main.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/rocker/rocker_main.c
b/drivers/net/ethernet/rocker/rocker_main.c
index e73e4fe..aeafdb9 100644
--- a/drivers/net/ethernet/rocker/rocker_main.c
+++ b/drivers/net/ethernet/rocker/rocker_main.c
@@ -1632,6 +1632,9 @@ rocker_world_port_obj_vlan_add(struct rocker_port
*rocker_port,
 {
 	struct rocker_world_ops *wops = rocker_port->rocker->wops;
 
+	if (netif_is_bridge_master(vlan->obj.orig_dev))
+		return -EOPNOTSUPP;
+
 	if (!wops->port_obj_vlan_add)
 		return -EOPNOTSUPP;
 
@@ -1647,6 +1650,9 @@ rocker_world_port_obj_vlan_del(struct rocker_port
*rocker_port,
 {
 	struct rocker_world_ops *wops = rocker_port->rocker->wops;
 
+	if (netif_is_bridge_master(vlan->obj.orig_dev))
+		return -EOPNOTSUPP;
+
 	if (!wops->port_obj_vlan_del)
 		return -EOPNOTSUPP;
 	return wops->port_obj_vlan_del(rocker_port, vlan);
-- 
2.4.11

Ignore VLAN events where the orig_dev is the bridge device itself.

Signed-off-by: Petr Machata <petrm at mellanox.com>
Reviewed-by: Vivien Didelot <vivien.didelot at savoirfairelinux.com>
---
 net/dsa/port.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/dsa/port.c b/net/dsa/port.c
index 2413beb..ed05954 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -252,6 +252,9 @@ int dsa_port_vlan_add(struct dsa_port *dp,
 		.vlan = vlan,
 	};
 
+	if (netif_is_bridge_master(vlan->obj.orig_dev))
+		return -EOPNOTSUPP;
+
 	if (br_vlan_enabled(dp->bridge_dev))
 		return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);
 
@@ -267,6 +270,9 @@ int dsa_port_vlan_del(struct dsa_port *dp,
 		.vlan = vlan,
 	};
 
+	if (netif_is_bridge_master(vlan->obj.orig_dev))
+		return -EOPNOTSUPP;
+
 	if (br_vlan_enabled(dp->bridge_dev))
 		return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);
 
-- 
2.4.11

Ignore VLAN events where the orig_dev is the bridge device itself.

Signed-off-by: Petr Machata <petrm at mellanox.com>
---
 drivers/staging/fsl-dpaa2/ethsw/ethsw.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/staging/fsl-dpaa2/ethsw/ethsw.c
b/drivers/staging/fsl-dpaa2/ethsw/ethsw.c
index c723a04..a17dd29 100644
--- a/drivers/staging/fsl-dpaa2/ethsw/ethsw.c
+++ b/drivers/staging/fsl-dpaa2/ethsw/ethsw.c
@@ -719,6 +719,9 @@ static int port_vlans_add(struct net_device *netdev,
 	struct ethsw_port_priv *port_priv = netdev_priv(netdev);
 	int vid, err;
 
+	if (netif_is_bridge_master(vlan->obj.orig_dev))
+		return -EOPNOTSUPP;
+
 	if (switchdev_trans_ph_prepare(trans))
 		return 0;
 
@@ -873,6 +876,9 @@ static int port_vlans_del(struct net_device *netdev,
 	struct ethsw_port_priv *port_priv = netdev_priv(netdev);
 	int vid, err;
 
+	if (netif_is_bridge_master(vlan->obj.orig_dev))
+		return -EOPNOTSUPP;
+
 	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++) {
 		err = ethsw_port_del_vlan(port_priv, vid);
 		if (err)
-- 
2.4.11

A driver might need to react to changes in settings of brentry VLANs.
Therefore send switchdev port notifications for these as well. Reuse
SWITCHDEV_OBJ_ID_PORT_VLAN for this purpose. Listeners should use
netif_is_bridge_master() on orig_dev to determine whether the
notification is about a bridge port or a bridge.

Signed-off-by: Petr Machata <petrm at mellanox.com>
Reviewed-by: Florian Fainelli <f.fainelli at gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot at savoirfairelinux.com>
Reviewed-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
Tested-by: Florian Fainelli <f.fainelli at gmail.com>
---
 net/bridge/br_vlan.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 8ad5756..b15ef3f 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -243,6 +243,10 @@ static int __vlan_add(struct net_bridge_vlan *v, u16 flags)
 			goto out_filt;
 		v->brvlan = masterv;
 		v->stats = masterv->stats;
+	} else {
+		err = br_switchdev_port_vlan_add(dev, v->vid, flags);
+		if (err && err != -EOPNOTSUPP)
+			goto out;
 	}
 
 	/* Add the dev mac and count the vlan only if it's usable */
@@ -278,6 +282,8 @@ static int __vlan_add(struct net_bridge_vlan *v, u16 flags)
 			br_vlan_put_master(masterv);
 			v->brvlan = NULL;
 		}
+	} else {
+		br_switchdev_port_vlan_del(dev, v->vid);
 	}
 
 	goto out;
@@ -303,6 +309,11 @@ static int __vlan_del(struct net_bridge_vlan *v)
 		err = __vlan_vid_del(p->dev, p->br, v->vid);
 		if (err)
 			goto out;
+	} else {
+		err = br_switchdev_port_vlan_del(v->br->dev, v->vid);
+		if (err && err != -EOPNOTSUPP)
+			goto out;
+		err = 0;
 	}
 
 	if (br_vlan_should_use(v)) {
@@ -580,6 +591,9 @@ int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags,
bool *changed)
 			vg->num_vlans++;
 			*changed = true;
 		}
+		ret = br_switchdev_port_vlan_add(br->dev, vid, flags);
+		if (ret && ret != -EOPNOTSUPP)
+			return ret;
 		if (__vlan_add_flags(vlan, flags))
 			*changed = true;
 
-- 
2.4.11

Since there's no special support for the bridge events, the driver
returns -EOPNOTSUPP, and thus the commit never happens. Therefore
schedule respin during the prepare stage: there's no real difference one
way or another.

This fixes the problem that mirror-to-gretap offload wouldn't adapt to
changes in bridge vlan configuration right away and another notification
would have to arrive for mlxsw to catch up.

Signed-off-by: Petr Machata <petrm at mellanox.com>
Reviewed-by: Ido Schimmel <idosch at mellanox.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
index cbc8fab..8a15ac4 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
@@ -1697,7 +1697,7 @@ static int mlxsw_sp_port_obj_add(struct net_device *dev,
 		vlan = SWITCHDEV_OBJ_PORT_VLAN(obj);
 		err = mlxsw_sp_port_vlans_add(mlxsw_sp_port, vlan, trans);
 
-		if (switchdev_trans_ph_commit(trans)) {
+		if (switchdev_trans_ph_prepare(trans)) {
 			/* The event is emitted before the changes are actually
 			 * applied to the bridge. Therefore schedule the respin
 			 * call for later, so that the respin logic sees the
-- 
2.4.11

On Mon, May 28, 2018 at 05:10:22PM +0200, Petr Machata
wrote:
> In commit 946a11e7408e ("mlxsw: spectrum_span: Allow bridge for gretap
> mirror"), mlxsw got support for offloading mirror-to-gretap such that
> the underlay packet path involves a bridge. In that case, the offload is
> also influenced by PVID setting of said bridge. However, changes to VLAN
> configuration of the bridge itself do not generate switchdev
> notifications, so there's no mechanism to prod mlxsw to update the
> offload when these settings change.
> 
> In this patchset, the problem is resolved by distributing the switchdev
> notification SWITCHDEV_OBJ_ID_PORT_VLAN also for configuration changes
> on bridge VLANs. Since stacked devices distribute the notification to
> lower devices, such event eventually reaches the driver, which can
> determine whether it's a bridge or port VLAN by inspecting orig_dev.
> 
> To keep things consistent, the newly-distributed notifications observe
> the same protocol as the existing ones: dual prepare/commit, with
> -EOPNOTSUPP indicating lack of support, even though there's currently
> nothing to prepare for and nothing to support. Correspondingly, all
> switchdev drivers have been updated to return -EOPNOTSUPP for bridge
> VLAN notifications.
> 
> In patch #1, the code to send notifications for adding and deleting is
> factored out into two named functions.
> 
> In patches #2-#5, respectively for mlxsw, rocker, DSA and DPAA2 ethsw,
> the new notifications (which are not enabled yet) are ignored to
> maintain the current behavior.
> 
It occured to me that I should read the cover letter and here are the
answers I was looking for.  But the cover letter isn't saved after the
commits are merged.  This should really be in the commit messages itself
so that we can look it up in the git history.
> In patch #6, the notification is actually enabled.
> 
> In patch #7, mlxsw is changed to update offloads of mirror-to-gre also
> for bridge-related notifications.
regards,
dan carpenter