Merge branch 'net-dsa-explicit-programmation-of-VLAN-on-CPU-ports'

Vivien Didelot says:

====================
net: dsa: explicit programmation of VLAN on CPU ports

When a VLAN is programmed on a user port, every switch of the fabric also
program the CPU ports and the DSA links as part of the VLAN. To do that,
DSA makes use of bitmaps to prepare all members of a VLAN.

While this is expected for DSA links which are used as conduit between
interconnected switches, only the dedicated CPU port of the slave must be
programmed, not all CPU ports of the fabric. This may also cause problems in
other corners of DSA such as the tag_8021q.c driver, which needs to program
its ports manually, CPU port included.

We need the dsa_port_vlan_{add,del} functions and its dsa_port_vid_{add,del}
variants to simply trigger the VLAN programmation without any logic in them,
but they may currently skip the operation based on the bridge device state.

This patchset gets rid of the bitmap operations, and moves the bridge device
check as well as the explicit programmation of CPU ports where they belong,
in the slave code.

While at it, clear the VLAN flags before programming a CPU port, as it
doesn't make sense to forward the PVID flag for example for such ports.

Changes in v2: only clear the PVID flag.
====================

Tested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dsa.h

@@ -275,9 +275,6 @@ struct dsa_switch {
 	 */
 	bool			vlan_filtering;
 
-	unsigned long		*bitmap;
-	unsigned long		_bitmap;
-
 	/* Dynamically allocated ports, keep last */
 	size_t num_ports;
 	struct dsa_port ports[];

net/dsa/dsa2.c

@@ -834,20 +834,6 @@ struct dsa_switch *dsa_switch_alloc(struct device *dev, size_t n)
 	if (!ds)
 		return NULL;
 
-	/* We avoid allocating memory outside dsa_switch
-	 * if it is not needed.
-	 */
-	if (n <= sizeof(ds->_bitmap) * 8) {
-		ds->bitmap = &ds->_bitmap;
-	} else {
-		ds->bitmap = devm_kcalloc(dev,
-					  BITS_TO_LONGS(n),
-					  sizeof(unsigned long),
-					  GFP_KERNEL);
-		if (unlikely(!ds->bitmap))
-			return NULL;
-	}
-
 	ds->dev = dev;
 	ds->num_ports = n;
 

net/dsa/port.c

@@ -348,10 +348,7 @@ int dsa_port_vlan_add(struct dsa_port *dp,
 		.vlan = vlan,
 	};
 
-	if (!dp->bridge_dev || br_vlan_enabled(dp->bridge_dev))
-		return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);
-
-	return 0;
+	return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);
 }
 
 int dsa_port_vlan_del(struct dsa_port *dp,
@@ -363,10 +360,7 @@ int dsa_port_vlan_del(struct dsa_port *dp,
 		.vlan = vlan,
 	};
 
-	if (!dp->bridge_dev || br_vlan_enabled(dp->bridge_dev))
-		return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);
-
-	return 0;
+	return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);
 }
 
 int dsa_port_vid_add(struct dsa_port *dp, u16 vid, u16 flags)
@@ -382,8 +376,8 @@ int dsa_port_vid_add(struct dsa_port *dp, u16 vid, u16 flags)
 
 	trans.ph_prepare = true;
 	err = dsa_port_vlan_add(dp, &vlan, &trans);
-	if (err == -EOPNOTSUPP)
-		return 0;
+	if (err)
+		return err;
 
 	trans.ph_prepare = false;
 	return dsa_port_vlan_add(dp, &vlan, &trans);

net/dsa/slave.c

@@ -312,6 +312,39 @@ static int dsa_slave_port_attr_set(struct net_device *dev,
 	return ret;
 }
 
+static int dsa_slave_vlan_add(struct net_device *dev,
+			      const struct switchdev_obj *obj,
+			      struct switchdev_trans *trans)
+{
+	struct dsa_port *dp = dsa_slave_to_port(dev);
+	struct switchdev_obj_port_vlan vlan;
+	int err;
+
+	if (obj->orig_dev != dev)
+		return -EOPNOTSUPP;
+
+	if (dp->bridge_dev && !br_vlan_enabled(dp->bridge_dev))
+		return 0;
+
+	vlan = *SWITCHDEV_OBJ_PORT_VLAN(obj);
+
+	err = dsa_port_vlan_add(dp, &vlan, trans);
+	if (err)
+		return err;
+
+	/* We need the dedicated CPU port to be a member of the VLAN as well.
+	 * Even though drivers often handle CPU membership in special ways,
+	 * it doesn't make sense to program a PVID, so clear this flag.
+	 */
+	vlan.flags &= ~BRIDGE_VLAN_INFO_PVID;
+
+	err = dsa_port_vlan_add(dp->cpu_dp, &vlan, trans);
+	if (err)
+		return err;
+
+	return 0;
+}
+
 static int dsa_slave_port_obj_add(struct net_device *dev,
 				  const struct switchdev_obj *obj,
 				  struct switchdev_trans *trans,
@@ -339,10 +372,7 @@ static int dsa_slave_port_obj_add(struct net_device *dev,
 				       trans);
 		break;
 	case SWITCHDEV_OBJ_ID_PORT_VLAN:
-		if (obj->orig_dev != dev)
-			return -EOPNOTSUPP;
-		err = dsa_port_vlan_add(dp, SWITCHDEV_OBJ_PORT_VLAN(obj),
-					trans);
+		err = dsa_slave_vlan_add(dev, obj, trans);
 		break;
 	default:
 		err = -EOPNOTSUPP;
@@ -352,6 +382,23 @@ static int dsa_slave_port_obj_add(struct net_device *dev,
 	return err;
 }
 
+static int dsa_slave_vlan_del(struct net_device *dev,
+			      const struct switchdev_obj *obj)
+{
+	struct dsa_port *dp = dsa_slave_to_port(dev);
+
+	if (obj->orig_dev != dev)
+		return -EOPNOTSUPP;
+
+	if (dp->bridge_dev && !br_vlan_enabled(dp->bridge_dev))
+		return 0;
+
+	/* Do not deprogram the CPU port as it may be shared with other user
+	 * ports which can be members of this VLAN as well.
+	 */
+	return dsa_port_vlan_del(dp, SWITCHDEV_OBJ_PORT_VLAN(obj));
+}
+
 static int dsa_slave_port_obj_del(struct net_device *dev,
 				  const struct switchdev_obj *obj)
 {
@@ -371,9 +418,7 @@ static int dsa_slave_port_obj_del(struct net_device *dev,
 		err = dsa_port_mdb_del(dp->cpu_dp, SWITCHDEV_OBJ_PORT_MDB(obj));
 		break;
 	case SWITCHDEV_OBJ_ID_PORT_VLAN:
-		if (obj->orig_dev != dev)
-			return -EOPNOTSUPP;
-		err = dsa_port_vlan_del(dp, SWITCHDEV_OBJ_PORT_VLAN(obj));
+		err = dsa_slave_vlan_del(dev, obj);
 		break;
 	default:
 		err = -EOPNOTSUPP;
@@ -1073,6 +1118,9 @@ static int dsa_slave_vlan_rx_add_vid(struct net_device *dev, __be16 proto,
 	 * need to emulate the switchdev prepare + commit phase.
 	 */
 	if (dp->bridge_dev) {
+		if (!br_vlan_enabled(dp->bridge_dev))
+			return 0;
+
 		/* br_vlan_get_info() returns -EINVAL or -ENOENT if the
 		 * device, respectively the VID is not found, returning
 		 * 0 means success, which is a failure for us here.
@@ -1082,8 +1130,15 @@ static int dsa_slave_vlan_rx_add_vid(struct net_device *dev, __be16 proto,
 			return -EBUSY;
 	}
 
-	/* This API only allows programming tagged, non-PVID VIDs */
-	return dsa_port_vid_add(dp, vid, 0);
+	ret = dsa_port_vid_add(dp, vid, 0);
+	if (ret && ret != -EOPNOTSUPP)
+		return ret;
+
+	ret = dsa_port_vid_add(dp->cpu_dp, vid, 0);
+	if (ret && ret != -EOPNOTSUPP)
+		return ret;
+
+	return 0;
 }
 
 static int dsa_slave_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
@@ -1097,6 +1152,9 @@ static int dsa_slave_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
 	 * need to emulate the switchdev prepare + commit phase.
 	 */
 	if (dp->bridge_dev) {
+		if (!br_vlan_enabled(dp->bridge_dev))
+			return 0;
+
 		/* br_vlan_get_info() returns -EINVAL or -ENOENT if the
 		 * device, respectively the VID is not found, returning
 		 * 0 means success, which is a failure for us here.
@@ -1110,6 +1168,9 @@ static int dsa_slave_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
 	if (ret == -EOPNOTSUPP)
 		ret = 0;
 
+	/* Do not deprogram the CPU port as it may be shared with other user
+	 * ports which can be members of this VLAN as well.
+	 */
 	return ret;
 }