Merge branch 'get-rid-of-the-switchdev-transactional-model'

Vladimir Oltean says:

====================
Get rid of the switchdev transactional model

Changes in v4:
- Fixed build error in dsa_loop and build warning in hellcreek driver.
- Scheduling the mlxsw SPAN work item regardless of the VLAN add return
  code, as per Ido's and Petr's request.

Changes in v3:
- Resolved a build warning in mv88e6xxx and tested that it actually
  works properly, which resulted in an extra patch (02/11).
- Addressed Ido's minor feedback in commit 10/11 relating to a comment.

Changes in v2:
- Got rid of the vid_begin -> vid_end range too from the switchdev API.
- Actually propagating errors from DSA MDB and VLAN notifiers.

This series comes after the late realization that the prepare/commit
separation imposed by switchdev does not help literally anybody:
https://patchwork.kernel.org/project/netdevbpf/patch/20201212203901.351331-1-vladimir.oltean@nxp.com/

We should kill it before it inflicts even more damage to the error
handling logic in drivers.

Also remove the unused VLAN ranges feature from the switchdev VLAN
objects, which simplifies all drivers by quite a bit.
====================

Link: https://lore.kernel.org/r/20210109000156.1246735-1-olteanv@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 19 insertions, 70 deletions

diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index 3fb362b6874e..21d2f842d068 100644
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -33,15 +33,12 @@ static int dsa_switch_ageing_time(struct dsa_switch *ds,
 				  struct dsa_notifier_ageing_time_info *info)
 {
 	unsigned int ageing_time = info->ageing_time;
-	struct switchdev_trans *trans = info->trans;
-
-	if (switchdev_trans_ph_prepare(trans)) {
-		if (ds->ageing_time_min && ageing_time < ds->ageing_time_min)
-			return -ERANGE;
-		if (ds->ageing_time_max && ageing_time > ds->ageing_time_max)
-			return -ERANGE;
-		return 0;
-	}
+
+	if (ds->ageing_time_min && ageing_time < ds->ageing_time_min)
+		return -ERANGE;
+
+	if (ds->ageing_time_max && ageing_time > ds->ageing_time_max)
+		return -ERANGE;
 
 	/* Program the fastest ageing time in case of multiple bridges */
 	ageing_time = dsa_switch_fastest_ageing_time(ds, ageing_time);
@@ -139,17 +136,8 @@ static int dsa_switch_bridge_leave(struct dsa_switch *ds,
 		}
 	}
 	if (unset_vlan_filtering) {
-		struct switchdev_trans trans;
-
-		trans.ph_prepare = true;
 		err = dsa_port_vlan_filtering(dsa_to_port(ds, info->port),
-					      false, &trans);
-		if (err && err != EOPNOTSUPP)
-			return err;
-
-		trans.ph_prepare = false;
-		err = dsa_port_vlan_filtering(dsa_to_port(ds, info->port),
-					      false, &trans);
+					      false);
 		if (err && err != EOPNOTSUPP)
 			return err;
 	}
@@ -190,41 +178,24 @@ static bool dsa_switch_mdb_match(struct dsa_switch *ds, int port,
 	return false;
 }
 
-static int dsa_switch_mdb_prepare(struct dsa_switch *ds,
-				  struct dsa_notifier_mdb_info *info)
+static int dsa_switch_mdb_add(struct dsa_switch *ds,
+			      struct dsa_notifier_mdb_info *info)
 {
-	int port, err;
+	int err = 0;
+	int port;
 
-	if (!ds->ops->port_mdb_prepare || !ds->ops->port_mdb_add)
+	if (!ds->ops->port_mdb_add)
 		return -EOPNOTSUPP;
 
 	for (port = 0; port < ds->num_ports; port++) {
 		if (dsa_switch_mdb_match(ds, port, info)) {
-			err = ds->ops->port_mdb_prepare(ds, port, info->mdb);
+			err = ds->ops->port_mdb_add(ds, port, info->mdb);
 			if (err)
-				return err;
+				break;
 		}
 	}
 
-	return 0;
-}
-
-static int dsa_switch_mdb_add(struct dsa_switch *ds,
-			      struct dsa_notifier_mdb_info *info)
-{
-	int port;
-
-	if (switchdev_trans_ph_prepare(info->trans))
-		return dsa_switch_mdb_prepare(ds, info);
-
-	if (!ds->ops->port_mdb_add)
-		return 0;
-
-	for (port = 0; port < ds->num_ports; port++)
-		if (dsa_switch_mdb_match(ds, port, info))
-			ds->ops->port_mdb_add(ds, port, info->mdb);
-
-	return 0;
+	return err;
 }
 
 static int dsa_switch_mdb_del(struct dsa_switch *ds,
@@ -251,17 +222,17 @@ static bool dsa_switch_vlan_match(struct dsa_switch *ds, int port,
 	return false;
 }
 
-static int dsa_switch_vlan_prepare(struct dsa_switch *ds,
-				   struct dsa_notifier_vlan_info *info)
+static int dsa_switch_vlan_add(struct dsa_switch *ds,
+			       struct dsa_notifier_vlan_info *info)
 {
 	int port, err;
 
-	if (!ds->ops->port_vlan_prepare || !ds->ops->port_vlan_add)
+	if (!ds->ops->port_vlan_add)
 		return -EOPNOTSUPP;
 
 	for (port = 0; port < ds->num_ports; port++) {
 		if (dsa_switch_vlan_match(ds, port, info)) {
-			err = ds->ops->port_vlan_prepare(ds, port, info->vlan);
+			err = ds->ops->port_vlan_add(ds, port, info->vlan);
 			if (err)
 				return err;
 		}
@@ -270,24 +241,6 @@ static int dsa_switch_vlan_prepare(struct dsa_switch *ds,
 	return 0;
 }
 
-static int dsa_switch_vlan_add(struct dsa_switch *ds,
-			       struct dsa_notifier_vlan_info *info)
-{
-	int port;
-
-	if (switchdev_trans_ph_prepare(info->trans))
-		return dsa_switch_vlan_prepare(ds, info);
-
-	if (!ds->ops->port_vlan_add)
-		return 0;
-
-	for (port = 0; port < ds->num_ports; port++)
-		if (dsa_switch_vlan_match(ds, port, info))
-			ds->ops->port_vlan_add(ds, port, info->vlan);
-
-	return 0;
-}
-
 static int dsa_switch_vlan_del(struct dsa_switch *ds,
 			       struct dsa_notifier_vlan_info *info)
 {
@@ -345,10 +298,6 @@ static int dsa_switch_event(struct notifier_block *nb,
 		break;
 	}
 
-	/* Non-switchdev operations cannot be rolled back. If a DSA driver
-	 * returns an error during the chained call, switch chips may be in an
-	 * inconsistent state.
-	 */
 	if (err)
 		dev_dbg(ds->dev, "breaking chain for DSA event %lu (%d)\n",
 			event, err);