net: switchdev: remove vid_begin -> vid_end range from VLAN objects

The call path of a switchdev VLAN addition to the bridge looks something
like this today:

        nbp_vlan_init
        |  __br_vlan_set_default_pvid
        |  |                       |
        |  |    br_afspec          |
        |  |        |              |
        |  |        v              |
        |  | br_process_vlan_info  |
        |  |        |              |
        |  |        v              |
        |  |   br_vlan_info        |
        |  |       / \            /
        |  |      /   \          /
        |  |     /     \        /
        |  |    /       \      /
        v  v   v         v    v
      nbp_vlan_add   br_vlan_add ------+
       |              ^      ^ |       |
       |             /       | |       |
       |            /       /  /       |
       \ br_vlan_get_master/  /        v
        \        ^        /  /  br_vlan_add_existing
         \       |       /  /          |
          \      |      /  /          /
           \     |     /  /          /
            \    |    /  /          /
             \   |   /  /          /
              v  |   | v          /
              __vlan_add         /
                 / |            /
                /  |           /
               v   |          /
   __vlan_vid_add  |         /
               \   |        /
                v  v        v
      br_switchdev_port_vlan_add

The ranges UAPI was introduced to the bridge in commit bdced7ef7838
("bridge: support for multiple vlans and vlan ranges in setlink and
dellink requests") (Jan 10 2015). But the VLAN ranges (parsed in br_afspec)
have always been passed one by one, through struct bridge_vlan_info
tmp_vinfo, to br_vlan_info. So the range never went too far in depth.

Then Scott Feldman introduced the switchdev_port_bridge_setlink function
in commit 47f8328bb1a4 ("switchdev: add new switchdev bridge setlink").
That marked the introduction of the SWITCHDEV_OBJ_PORT_VLAN, which made
full use of the range. But switchdev_port_bridge_setlink was called like
this:

br_setlink
-> br_afspec
-> switchdev_port_bridge_setlink

Basically, the switchdev and the bridge code were not tightly integrated.
Then commit 41c498b9359e ("bridge: restore br_setlink back to original")
came, and switchdev drivers were required to implement
.ndo_bridge_setlink = switchdev_port_bridge_setlink for a while.

In the meantime, commits such as 0944d6b5a2fa ("bridge: try switchdev op
first in __vlan_vid_add/del") finally made switchdev penetrate the
br_vlan_info() barrier and start to develop the call path we have today.
But remember, br_vlan_info() still receives VLANs one by one.

Then Arkadi Sharshevsky refactored the switchdev API in 2017 in commit
29ab586c3d83 ("net: switchdev: Remove bridge bypass support from
switchdev") so that drivers would not implement .ndo_bridge_setlink any
longer. The switchdev_port_bridge_setlink also got deleted.
This refactoring removed the parallel bridge_setlink implementation from
switchdev, and left the only switchdev VLAN objects to be the ones
offloaded from __vlan_vid_add (basically RX filtering) and  __vlan_add
(the latter coming from commit 9c86ce2c1ae3 ("net: bridge: Notify about
bridge VLANs")).

That is to say, today the switchdev VLAN object ranges are not used in
the kernel. Refactoring the above call path is a bit complicated, when
the bridge VLAN call path is already a bit complicated.

Let's go off and finish the job of commit 29ab586c3d83 by deleting the
bogus iteration through the VLAN ranges from the drivers. Some aspects
of this feature never made too much sense in the first place. For
example, what is a range of VLANs all having the BRIDGE_VLAN_INFO_PVID
flag supposed to mean, when a port can obviously have a single pvid?
This particular configuration _is_ denied as of commit 6623c60dc28e
("bridge: vlan: enforce no pvid flag in vlan ranges"), but from an API
perspective, the driver still has to play pretend, and only offload the
vlan->vid_end as pvid. And the addition of a switchdev VLAN object can
modify the flags of another, completely unrelated, switchdev VLAN
object! (a VLAN that is PVID will invalidate the PVID flag from whatever
other VLAN had previously been offloaded with switchdev and had that
flag. Yet switchdev never notifies about that change, drivers are
supposed to guess).

Nonetheless, having a VLAN range in the API makes error handling look
scarier than it really is - unwinding on errors and all of that.
When in reality, no one really calls this API with more than one VLAN.
It is all unnecessary complexity.

And despite appearing pretentious (two-phase transactional model and
all), the switchdev API is really sloppy because the VLAN addition and
removal operations are not paired with one another (you can add a VLAN
100 times and delete it just once). The bridge notifies through
switchdev of a VLAN addition not only when the flags of an existing VLAN
change, but also when nothing changes. There are switchdev drivers out
there who don't like adding a VLAN that has already been added, and
those checks don't really belong at driver level. But the fact that the
API contains ranges is yet another factor that prevents this from being
addressed in the future.

Of the existing switchdev pieces of hardware, it appears that only
Mellanox Spectrum supports offloading more than one VLAN at a time,
through mlxsw_sp_port_vlan_set. I have kept that code internal to the
driver, because there is some more bookkeeping that makes use of it, but
I deleted it from the switchdev API. But since the switchdev support for
ranges has already been de facto deleted by a Mellanox employee and
nobody noticed for 4 years, I'm going to assume it's not a biggie.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com> # switchdev and mlxsw
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> # hellcreek
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

5 files changed, 37 insertions, 138 deletions

diff --git a/drivers/net/ethernet/marvell/prestera/prestera_switchdev.c b/drivers/net/ethernet/marvell/prestera/prestera_switchdev.c
index 7d83e1f91ef1..c87667c1cca0 100644
--- a/drivers/net/ethernet/marvell/prestera/prestera_switchdev.c
+++ b/drivers/net/ethernet/marvell/prestera/prestera_switchdev.c
@@ -1045,17 +1045,9 @@ static int prestera_port_vlans_add(struct prestera_port *port,
 	if (!bridge->vlan_enabled)
 		return 0;
 
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++) {
-		int err;
-
-		err = prestera_bridge_port_vlan_add(port, br_port,
-						    vid, flag_untagged,
-						    flag_pvid, extack);
-		if (err)
-			return err;
-	}
-
-	return 0;
+	return prestera_bridge_port_vlan_add(port, br_port,
+					     vid, flag_untagged,
+					     flag_pvid, extack);
 }
 
 static int prestera_port_obj_add(struct net_device *dev,
@@ -1081,7 +1073,6 @@ static int prestera_port_vlans_del(struct prestera_port *port,
 	struct net_device *dev = vlan->obj.orig_dev;
 	struct prestera_bridge_port *br_port;
 	struct prestera_switch *sw = port->sw;
-	u16 vid;
 
 	if (netif_is_bridge_master(dev))
 		return -EOPNOTSUPP;
@@ -1093,8 +1084,7 @@ static int prestera_port_vlans_del(struct prestera_port *port,
 	if (!br_port->bridge->vlan_enabled)
 		return 0;
 
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++)
-		prestera_bridge_port_vlan_del(port, br_port, vid);
+	prestera_bridge_port_vlan_del(port, br_port, vlan->vid);
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
index cea42f6ed89b..7039cff69680 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
@@ -1211,23 +1211,20 @@ mlxsw_sp_br_ban_rif_pvid_change(struct mlxsw_sp *mlxsw_sp,
 				const struct switchdev_obj_port_vlan *vlan)
 {
 	u16 pvid;
-	u16 vid;
 
 	pvid = mlxsw_sp_rif_vid(mlxsw_sp, br_dev);
 	if (!pvid)
 		return 0;
 
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
-		if (vlan->flags & BRIDGE_VLAN_INFO_PVID) {
-			if (vid != pvid) {
-				netdev_err(br_dev, "Can't change PVID, it's used by router interface\n");
-				return -EBUSY;
-			}
-		} else {
-			if (vid == pvid) {
-				netdev_err(br_dev, "Can't remove PVID, it's used by router interface\n");
-				return -EBUSY;
-			}
+	if (vlan->flags & BRIDGE_VLAN_INFO_PVID) {
+		if (vlan->vid != pvid) {
+			netdev_err(br_dev, "Can't change PVID, it's used by router interface\n");
+			return -EBUSY;
+		}
+	} else {
+		if (vlan->vid == pvid) {
+			netdev_err(br_dev, "Can't remove PVID, it's used by router interface\n");
+			return -EBUSY;
 		}
 	}
 
@@ -1244,7 +1241,6 @@ static int mlxsw_sp_port_vlans_add(struct mlxsw_sp_port *mlxsw_sp_port,
 	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
 	struct net_device *orig_dev = vlan->obj.orig_dev;
 	struct mlxsw_sp_bridge_port *bridge_port;
-	u16 vid;
 
 	if (netif_is_bridge_master(orig_dev)) {
 		int err = 0;
@@ -1269,17 +1265,9 @@ static int mlxsw_sp_port_vlans_add(struct mlxsw_sp_port *mlxsw_sp_port,
 	if (!bridge_port->bridge_device->vlan_enabled)
 		return 0;
 
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++) {
-		int err;
-
-		err = mlxsw_sp_bridge_port_vlan_add(mlxsw_sp_port, bridge_port,
-						    vid, flag_untagged,
-						    flag_pvid, extack);
-		if (err)
-			return err;
-	}
-
-	return 0;
+	return mlxsw_sp_bridge_port_vlan_add(mlxsw_sp_port, bridge_port,
+					     vlan->vid, flag_untagged,
+					     flag_pvid, extack);
 }
 
 static enum mlxsw_reg_sfdf_flush_type mlxsw_sp_fdb_flush_type(bool lagged)
@@ -1873,7 +1861,6 @@ static int mlxsw_sp_port_vlans_del(struct mlxsw_sp_port *mlxsw_sp_port,
 	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
 	struct net_device *orig_dev = vlan->obj.orig_dev;
 	struct mlxsw_sp_bridge_port *bridge_port;
-	u16 vid;
 
 	if (netif_is_bridge_master(orig_dev))
 		return -EOPNOTSUPP;
@@ -1885,8 +1872,7 @@ static int mlxsw_sp_port_vlans_del(struct mlxsw_sp_port *mlxsw_sp_port,
 	if (!bridge_port->bridge_device->vlan_enabled)
 		return 0;
 
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++)
-		mlxsw_sp_bridge_port_vlan_del(mlxsw_sp_port, bridge_port, vid);
+	mlxsw_sp_bridge_port_vlan_del(mlxsw_sp_port, bridge_port, vlan->vid);
 
 	return 0;
 }
@@ -3411,7 +3397,6 @@ mlxsw_sp_switchdev_vxlan_vlans_add(struct net_device *vxlan_dev,
 	struct netlink_ext_ack *extack;
 	struct mlxsw_sp *mlxsw_sp;
 	struct net_device *br_dev;
-	u16 vid;
 
 	extack = switchdev_notifier_info_to_extack(&port_obj_info->info);
 	br_dev = netdev_master_upper_dev_get(vxlan_dev);
@@ -3434,18 +3419,10 @@ mlxsw_sp_switchdev_vxlan_vlans_add(struct net_device *vxlan_dev,
 	if (!bridge_device->vlan_enabled)
 		return 0;
 
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++) {
-		int err;
-
-		err = mlxsw_sp_switchdev_vxlan_vlan_add(mlxsw_sp, bridge_device,
-							vxlan_dev, vid,
-							flag_untagged,
-							flag_pvid, extack);
-		if (err)
-			return err;
-	}
-
-	return 0;
+	return mlxsw_sp_switchdev_vxlan_vlan_add(mlxsw_sp, bridge_device,
+						 vxlan_dev, vlan->vid,
+						 flag_untagged,
+						 flag_pvid, extack);
 }
 
 static void
@@ -3458,7 +3435,6 @@ mlxsw_sp_switchdev_vxlan_vlans_del(struct net_device *vxlan_dev,
 	struct mlxsw_sp_bridge_device *bridge_device;
 	struct mlxsw_sp *mlxsw_sp;
 	struct net_device *br_dev;
-	u16 vid;
 
 	br_dev = netdev_master_upper_dev_get(vxlan_dev);
 	if (!br_dev)
@@ -3477,9 +3453,8 @@ mlxsw_sp_switchdev_vxlan_vlans_del(struct net_device *vxlan_dev,
 	if (!bridge_device->vlan_enabled)
 		return;
 
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++)
-		mlxsw_sp_switchdev_vxlan_vlan_del(mlxsw_sp, bridge_device,
-						  vxlan_dev, vid);
+	mlxsw_sp_switchdev_vxlan_vlan_del(mlxsw_sp, bridge_device, vxlan_dev,
+					  vlan->vid);
 }
 
 static int
diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 2bd2840d88bd..3b8718b143bb 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -893,39 +893,16 @@ static int ocelot_port_obj_add_vlan(struct net_device *dev,
 				    const struct switchdev_obj_port_vlan *vlan,
 				    struct switchdev_trans *trans)
 {
+	bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
+	bool pvid = vlan->flags & BRIDGE_VLAN_INFO_PVID;
 	int ret;
-	u16 vid;
-
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++) {
-		bool pvid = vlan->flags & BRIDGE_VLAN_INFO_PVID;
-		bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
-
-		if (switchdev_trans_ph_prepare(trans))
-			ret = ocelot_vlan_vid_prepare(dev, vid, pvid,
-						      untagged);
-		else
-			ret = ocelot_vlan_vid_add(dev, vid, pvid, untagged);
-		if (ret)
-			return ret;
-	}
-
-	return 0;
-}
-
-static int ocelot_port_vlan_del_vlan(struct net_device *dev,
-				     const struct switchdev_obj_port_vlan *vlan)
-{
-	int ret;
-	u16 vid;
 
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++) {
-		ret = ocelot_vlan_vid_del(dev, vid);
-
-		if (ret)
-			return ret;
-	}
+	if (switchdev_trans_ph_prepare(trans))
+		ret = ocelot_vlan_vid_prepare(dev, vlan->vid, pvid, untagged);
+	else
+		ret = ocelot_vlan_vid_add(dev, vlan->vid, pvid, untagged);
 
-	return 0;
+	return ret;
 }
 
 static int ocelot_port_obj_add_mdb(struct net_device *dev,
@@ -985,8 +962,8 @@ static int ocelot_port_obj_del(struct net_device *dev,
 
 	switch (obj->id) {
 	case SWITCHDEV_OBJ_ID_PORT_VLAN:
-		ret = ocelot_port_vlan_del_vlan(dev,
-						SWITCHDEV_OBJ_PORT_VLAN(obj));
+		ret = ocelot_vlan_vid_del(dev,
+					  SWITCHDEV_OBJ_PORT_VLAN(obj)->vid);
 		break;
 	case SWITCHDEV_OBJ_ID_PORT_MDB:
 		ret = ocelot_port_obj_del_mdb(dev, SWITCHDEV_OBJ_PORT_MDB(obj));
diff --git a/drivers/net/ethernet/rocker/rocker_ofdpa.c b/drivers/net/ethernet/rocker/rocker_ofdpa.c
index 7072b249c8bd..d9d5188b7627 100644
--- a/drivers/net/ethernet/rocker/rocker_ofdpa.c
+++ b/drivers/net/ethernet/rocker/rocker_ofdpa.c
@@ -2540,32 +2540,16 @@ static int ofdpa_port_obj_vlan_add(struct rocker_port *rocker_port,
 				   const struct switchdev_obj_port_vlan *vlan)
 {
 	struct ofdpa_port *ofdpa_port = rocker_port->wpriv;
-	u16 vid;
-	int err;
 
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++) {
-		err = ofdpa_port_vlan_add(ofdpa_port, vid, vlan->flags);
-		if (err)
-			return err;
-	}
-
-	return 0;
+	return ofdpa_port_vlan_add(ofdpa_port, vlan->vid, vlan->flags);
 }
 
 static int ofdpa_port_obj_vlan_del(struct rocker_port *rocker_port,
 				   const struct switchdev_obj_port_vlan *vlan)
 {
 	struct ofdpa_port *ofdpa_port = rocker_port->wpriv;
-	u16 vid;
-	int err;
 
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++) {
-		err = ofdpa_port_vlan_del(ofdpa_port, vid, vlan->flags);
-		if (err)
-			return err;
-	}
-
-	return 0;
+	return ofdpa_port_vlan_del(ofdpa_port, vlan->vid, vlan->flags);
 }
 
 static int ofdpa_port_obj_fdb_add(struct rocker_port *rocker_port,
diff --git a/drivers/net/ethernet/ti/cpsw_switchdev.c b/drivers/net/ethernet/ti/cpsw_switchdev.c
index 29747da5c514..8a36228acc5d 100644
--- a/drivers/net/ethernet/ti/cpsw_switchdev.c
+++ b/drivers/net/ethernet/ti/cpsw_switchdev.c
@@ -260,10 +260,9 @@ static int cpsw_port_vlans_add(struct cpsw_priv *priv,
 	struct net_device *orig_dev = vlan->obj.orig_dev;
 	bool cpu_port = netif_is_bridge_master(orig_dev);
 	bool pvid = vlan->flags & BRIDGE_VLAN_INFO_PVID;
-	u16 vid;
 
 	dev_dbg(priv->dev, "VID add: %s: vid:%u flags:%X\n",
-		priv->ndev->name, vlan->vid_begin, vlan->flags);
+		priv->ndev->name, vlan->vid, vlan->flags);
 
 	if (cpu_port && !(vlan->flags & BRIDGE_VLAN_INFO_BRENTRY))
 		return 0;
@@ -271,33 +270,7 @@ static int cpsw_port_vlans_add(struct cpsw_priv *priv,
 	if (switchdev_trans_ph_prepare(trans))
 		return 0;
 
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++) {
-		int err;
-
-		err = cpsw_port_vlan_add(priv, untag, pvid, vid, orig_dev);
-		if (err)
-			return err;
-	}
-
-	return 0;
-}
-
-static int cpsw_port_vlans_del(struct cpsw_priv *priv,
-			       const struct switchdev_obj_port_vlan *vlan)
-
-{
-	struct net_device *orig_dev = vlan->obj.orig_dev;
-	u16 vid;
-
-	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++) {
-		int err;
-
-		err = cpsw_port_vlan_del(priv, vid, orig_dev);
-		if (err)
-			return err;
-	}
-
-	return 0;
+	return cpsw_port_vlan_add(priv, untag, pvid, vlan->vid, orig_dev);
 }
 
 static int cpsw_port_mdb_add(struct cpsw_priv *priv,
@@ -392,7 +365,7 @@ static int cpsw_port_obj_del(struct net_device *ndev,
 
 	switch (obj->id) {
 	case SWITCHDEV_OBJ_ID_PORT_VLAN:
-		err = cpsw_port_vlans_del(priv, vlan);
+		err = cpsw_port_vlan_del(priv, vlan->vid, vlan->obj.orig_dev);
 		break;
 	case SWITCHDEV_OBJ_ID_PORT_MDB:
 	case SWITCHDEV_OBJ_ID_HOST_MDB: