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, 42 insertions, 61 deletions

diff --git a/net/dsa/port.c b/net/dsa/port.c
index 73569c9af3cc..e59bf66c4c0d 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -40,17 +40,15 @@ static int dsa_port_notify(const struct dsa_port *dp, unsigned long e, void *v)
 	return notifier_to_errno(err);
 }
 
-int dsa_port_set_state(struct dsa_port *dp, u8 state,
-		       struct switchdev_trans *trans)
+int dsa_port_set_state(struct dsa_port *dp, u8 state)
 {
 	struct dsa_switch *ds = dp->ds;
 	int port = dp->index;
 
-	if (switchdev_trans_ph_prepare(trans))
-		return ds->ops->port_stp_state_set ? 0 : -EOPNOTSUPP;
+	if (!ds->ops->port_stp_state_set)
+		return -EOPNOTSUPP;
 
-	if (ds->ops->port_stp_state_set)
-		ds->ops->port_stp_state_set(ds, port, state);
+	ds->ops->port_stp_state_set(ds, port, state);
 
 	if (ds->ops->port_fast_age) {
 		/* Fast age FDB entries or flush appropriate forwarding database
@@ -75,7 +73,7 @@ static void dsa_port_set_state_now(struct dsa_port *dp, u8 state)
 {
 	int err;
 
-	err = dsa_port_set_state(dp, state, NULL);
+	err = dsa_port_set_state(dp, state);
 	if (err)
 		pr_err("DSA: failed to set STP state %u (%d)\n", state, err);
 }
@@ -145,7 +143,7 @@ int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br)
 	int err;
 
 	/* Set the flooding mode before joining the port in the switch */
-	err = dsa_port_bridge_flags(dp, BR_FLOOD | BR_MCAST_FLOOD, NULL);
+	err = dsa_port_bridge_flags(dp, BR_FLOOD | BR_MCAST_FLOOD);
 	if (err)
 		return err;
 
@@ -158,7 +156,7 @@ int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br)
 
 	/* The bridging is rolled back on error */
 	if (err) {
-		dsa_port_bridge_flags(dp, 0, NULL);
+		dsa_port_bridge_flags(dp, 0);
 		dp->bridge_dev = NULL;
 	}
 
@@ -185,7 +183,7 @@ void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br)
 		pr_err("DSA: failed to notify DSA_NOTIFIER_BRIDGE_LEAVE\n");
 
 	/* Port is leaving the bridge, disable flooding */
-	dsa_port_bridge_flags(dp, 0, NULL);
+	dsa_port_bridge_flags(dp, 0);
 
 	/* Port left the bridge, put in BR_STATE_DISABLED by the bridge layer,
 	 * so allow it to be in BR_STATE_FORWARDING to be kept functional
@@ -259,43 +257,36 @@ static bool dsa_port_can_apply_vlan_filtering(struct dsa_port *dp,
 	return true;
 }
 
-int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
-			    struct switchdev_trans *trans)
+int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering)
 {
 	struct dsa_switch *ds = dp->ds;
+	bool apply;
 	int err;
 
-	if (switchdev_trans_ph_prepare(trans)) {
-		bool apply;
-
-		if (!ds->ops->port_vlan_filtering)
-			return -EOPNOTSUPP;
+	if (!ds->ops->port_vlan_filtering)
+		return -EOPNOTSUPP;
 
-		/* We are called from dsa_slave_switchdev_blocking_event(),
-		 * which is not under rcu_read_lock(), unlike
-		 * dsa_slave_switchdev_event().
-		 */
-		rcu_read_lock();
-		apply = dsa_port_can_apply_vlan_filtering(dp, vlan_filtering);
-		rcu_read_unlock();
-		if (!apply)
-			return -EINVAL;
-	}
+	/* We are called from dsa_slave_switchdev_blocking_event(),
+	 * which is not under rcu_read_lock(), unlike
+	 * dsa_slave_switchdev_event().
+	 */
+	rcu_read_lock();
+	apply = dsa_port_can_apply_vlan_filtering(dp, vlan_filtering);
+	rcu_read_unlock();
+	if (!apply)
+		return -EINVAL;
 
 	if (dsa_port_is_vlan_filtering(dp) == vlan_filtering)
 		return 0;
 
-	err = ds->ops->port_vlan_filtering(ds, dp->index, vlan_filtering,
-					   trans);
+	err = ds->ops->port_vlan_filtering(ds, dp->index, vlan_filtering);
 	if (err)
 		return err;
 
-	if (switchdev_trans_ph_commit(trans)) {
-		if (ds->vlan_filtering_is_global)
-			ds->vlan_filtering = vlan_filtering;
-		else
-			dp->vlan_filtering = vlan_filtering;
-	}
+	if (ds->vlan_filtering_is_global)
+		ds->vlan_filtering = vlan_filtering;
+	else
+		dp->vlan_filtering = vlan_filtering;
 
 	return 0;
 }
@@ -314,26 +305,25 @@ bool dsa_port_skip_vlan_configuration(struct dsa_port *dp)
 		!br_vlan_enabled(dp->bridge_dev));
 }
 
-int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
-			 struct switchdev_trans *trans)
+int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock)
 {
 	unsigned long ageing_jiffies = clock_t_to_jiffies(ageing_clock);
 	unsigned int ageing_time = jiffies_to_msecs(ageing_jiffies);
-	struct dsa_notifier_ageing_time_info info = {
-		.ageing_time = ageing_time,
-		.trans = trans,
-	};
+	struct dsa_notifier_ageing_time_info info;
+	int err;
 
-	if (switchdev_trans_ph_prepare(trans))
-		return dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);
+	info.ageing_time = ageing_time;
+
+	err = dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);
+	if (err)
+		return err;
 
 	dp->ageing_time = ageing_time;
 
-	return dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);
+	return 0;
 }
 
-int dsa_port_pre_bridge_flags(const struct dsa_port *dp, unsigned long flags,
-			      struct switchdev_trans *trans)
+int dsa_port_pre_bridge_flags(const struct dsa_port *dp, unsigned long flags)
 {
 	struct dsa_switch *ds = dp->ds;
 
@@ -344,16 +334,12 @@ int dsa_port_pre_bridge_flags(const struct dsa_port *dp, unsigned long flags,
 	return 0;
 }
 
-int dsa_port_bridge_flags(const struct dsa_port *dp, unsigned long flags,
-			  struct switchdev_trans *trans)
+int dsa_port_bridge_flags(const struct dsa_port *dp, unsigned long flags)
 {
 	struct dsa_switch *ds = dp->ds;
 	int port = dp->index;
 	int err = 0;
 
-	if (switchdev_trans_ph_prepare(trans))
-		return 0;
-
 	if (ds->ops->port_egress_floods)
 		err = ds->ops->port_egress_floods(ds, port, flags & BR_FLOOD,
 						  flags & BR_MCAST_FLOOD);
@@ -361,14 +347,13 @@ int dsa_port_bridge_flags(const struct dsa_port *dp, unsigned long flags,
 	return err;
 }
 
-int dsa_port_mrouter(struct dsa_port *dp, bool mrouter,
-		     struct switchdev_trans *trans)
+int dsa_port_mrouter(struct dsa_port *dp, bool mrouter)
 {
 	struct dsa_switch *ds = dp->ds;
 	int port = dp->index;
 
-	if (switchdev_trans_ph_prepare(trans))
-		return ds->ops->port_egress_floods ? 0 : -EOPNOTSUPP;
+	if (!ds->ops->port_egress_floods)
+		return -EOPNOTSUPP;
 
 	return ds->ops->port_egress_floods(ds, port, true, mrouter);
 }
@@ -425,13 +410,11 @@ int dsa_port_fdb_dump(struct dsa_port *dp, dsa_fdb_dump_cb_t *cb, void *data)
 }
 
 int dsa_port_mdb_add(const struct dsa_port *dp,
-		     const struct switchdev_obj_port_mdb *mdb,
-		     struct switchdev_trans *trans)
+		     const struct switchdev_obj_port_mdb *mdb)
 {
 	struct dsa_notifier_mdb_info info = {
 		.sw_index = dp->ds->index,
 		.port = dp->index,
-		.trans = trans,
 		.mdb = mdb,
 	};
 
@@ -451,13 +434,11 @@ int dsa_port_mdb_del(const struct dsa_port *dp,
 }
 
 int dsa_port_vlan_add(struct dsa_port *dp,
-		      const struct switchdev_obj_port_vlan *vlan,
-		      struct switchdev_trans *trans)
+		      const struct switchdev_obj_port_vlan *vlan)
 {
 	struct dsa_notifier_vlan_info info = {
 		.sw_index = dp->ds->index,
 		.port = dp->index,
-		.trans = trans,
 		.vlan = vlan,
 	};