net: dsa: remove the transactional logic from MDB entries

For many drivers, the .port_mdb_prepare callback was not a good opportunity
to avoid any error condition, and they would suppress errors found during
the actual commit phase.

Where a logical separation between the prepare and the commit phase
existed, the function that used to implement the .port_mdb_prepare
callback still exists, but now it is called directly from .port_mdb_add,
which was modified to return an int code.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> # hellcreek
Reviewed-by: Linus Wallei <linus.walleij@linaro.org> # RTL8366
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/b53/b53_common.c

@@ -1741,7 +1741,7 @@ int b53_fdb_dump(struct dsa_switch *ds, int port,
 }
 EXPORT_SYMBOL(b53_fdb_dump);
 
-int b53_mdb_prepare(struct dsa_switch *ds, int port,
+int b53_mdb_add(struct dsa_switch *ds, int port,
 		const struct switchdev_obj_port_mdb *mdb)
 {
 	struct b53_device *priv = ds->priv;
@@ -1752,19 +1752,7 @@ int b53_mdb_prepare(struct dsa_switch *ds, int port,
 	if (is5325(priv) || is5365(priv))
 		return -EOPNOTSUPP;
 
-	return 0;
-}
-EXPORT_SYMBOL(b53_mdb_prepare);
-
-void b53_mdb_add(struct dsa_switch *ds, int port,
-		 const struct switchdev_obj_port_mdb *mdb)
-{
-	struct b53_device *priv = ds->priv;
-	int ret;
-
-	ret = b53_arl_op(priv, 0, port, mdb->addr, mdb->vid, true);
-	if (ret)
-		dev_err(ds->dev, "failed to add MDB entry\n");
+	return b53_arl_op(priv, 0, port, mdb->addr, mdb->vid, true);
 }
 EXPORT_SYMBOL(b53_mdb_add);
 
@@ -2205,7 +2193,6 @@ static const struct dsa_switch_ops b53_switch_ops = {
 	.port_fdb_del		= b53_fdb_del,
 	.port_mirror_add	= b53_mirror_add,
 	.port_mirror_del	= b53_mirror_del,
-	.port_mdb_prepare	= b53_mdb_prepare,
 	.port_mdb_add		= b53_mdb_add,
 	.port_mdb_del		= b53_mdb_del,
 	.port_max_mtu		= b53_get_max_mtu,

drivers/net/dsa/b53/b53_priv.h

@@ -361,9 +361,7 @@ int b53_fdb_del(struct dsa_switch *ds, int port,
 		const unsigned char *addr, u16 vid);
 int b53_fdb_dump(struct dsa_switch *ds, int port,
 		 dsa_fdb_dump_cb_t *cb, void *data);
-int b53_mdb_prepare(struct dsa_switch *ds, int port,
-		    const struct switchdev_obj_port_mdb *mdb);
-void b53_mdb_add(struct dsa_switch *ds, int port,
+int b53_mdb_add(struct dsa_switch *ds, int port,
 		const struct switchdev_obj_port_mdb *mdb);
 int b53_mdb_del(struct dsa_switch *ds, int port,
 		const struct switchdev_obj_port_mdb *mdb);

drivers/net/dsa/bcm_sf2.c

@@ -1126,7 +1126,6 @@ static const struct dsa_switch_ops bcm_sf2_ops = {
 	.set_rxnfc		= bcm_sf2_set_rxnfc,
 	.port_mirror_add	= b53_mirror_add,
 	.port_mirror_del	= b53_mirror_del,
-	.port_mdb_prepare	= b53_mdb_prepare,
 	.port_mdb_add		= b53_mdb_add,
 	.port_mdb_del		= b53_mdb_del,
 };

drivers/net/dsa/lan9303-core.c

@@ -1232,14 +1232,19 @@ static int lan9303_port_mdb_prepare(struct dsa_switch *ds, int port,
 	return 0;
 }
 
-static void lan9303_port_mdb_add(struct dsa_switch *ds, int port,
+static int lan9303_port_mdb_add(struct dsa_switch *ds, int port,
 				const struct switchdev_obj_port_mdb *mdb)
 {
 	struct lan9303 *chip = ds->priv;
+	int err;
+
+	err = lan9303_port_mdb_prepare(ds, port, mdb);
+	if (err)
+		return err;
 
 	dev_dbg(chip->dev, "%s(%d, %pM, %d)\n", __func__, port, mdb->addr,
 		mdb->vid);
-	lan9303_alr_add_port(chip, mdb->addr, port, false);
+	return lan9303_alr_add_port(chip, mdb->addr, port, false);
 }
 
 static int lan9303_port_mdb_del(struct dsa_switch *ds, int port,
@@ -1274,7 +1279,6 @@ static const struct dsa_switch_ops lan9303_switch_ops = {
 	.port_fdb_add           = lan9303_port_fdb_add,
 	.port_fdb_del           = lan9303_port_fdb_del,
 	.port_fdb_dump          = lan9303_port_fdb_dump,
-	.port_mdb_prepare       = lan9303_port_mdb_prepare,
 	.port_mdb_add           = lan9303_port_mdb_add,
 	.port_mdb_del           = lan9303_port_mdb_del,
 };

drivers/net/dsa/microchip/ksz8795.c

@@ -1114,7 +1114,6 @@ static const struct dsa_switch_ops ksz8795_switch_ops = {
 	.port_vlan_add		= ksz8795_port_vlan_add,
 	.port_vlan_del		= ksz8795_port_vlan_del,
 	.port_fdb_dump		= ksz_port_fdb_dump,
-	.port_mdb_prepare       = ksz_port_mdb_prepare,
 	.port_mdb_add           = ksz_port_mdb_add,
 	.port_mdb_del           = ksz_port_mdb_del,
 	.port_mirror_add	= ksz8795_port_mirror_add,

drivers/net/dsa/microchip/ksz9477.c

@@ -774,7 +774,7 @@ static int ksz9477_port_fdb_dump(struct dsa_switch *ds, int port,
 	return ret;
 }
 
-static void ksz9477_port_mdb_add(struct dsa_switch *ds, int port,
+static int ksz9477_port_mdb_add(struct dsa_switch *ds, int port,
 				const struct switchdev_obj_port_mdb *mdb)
 {
 	struct ksz_device *dev = ds->priv;
@@ -782,6 +782,7 @@ static void ksz9477_port_mdb_add(struct dsa_switch *ds, int port,
 	u32 data;
 	int index;
 	u32 mac_hi, mac_lo;
+	int err = 0;
 
 	mac_hi = ((mdb->addr[0] << 8) | mdb->addr[1]);
 	mac_lo = ((mdb->addr[2] << 24) | (mdb->addr[3] << 16));
@@ -796,7 +797,8 @@ static void ksz9477_port_mdb_add(struct dsa_switch *ds, int port,
 		ksz_write32(dev, REG_SW_ALU_STAT_CTRL__4, data);
 
 		/* wait to be finished */
-		if (ksz9477_wait_alu_sta_ready(dev)) {
+		err = ksz9477_wait_alu_sta_ready(dev);
+		if (err) {
 			dev_dbg(dev->dev, "Failed to read ALU STATIC\n");
 			goto exit;
 		}
@@ -819,8 +821,10 @@ static void ksz9477_port_mdb_add(struct dsa_switch *ds, int port,
 	}
 
 	/* no available entry */
-	if (index == dev->num_statics)
+	if (index == dev->num_statics) {
+		err = -ENOSPC;
 		goto exit;
+	}
 
 	/* add entry */
 	static_table[0] = ALU_V_STATIC_VALID;
@@ -842,6 +846,7 @@ static void ksz9477_port_mdb_add(struct dsa_switch *ds, int port,
 
 exit:
 	mutex_unlock(&dev->alu_mutex);
+	return err;
 }
 
 static int ksz9477_port_mdb_del(struct dsa_switch *ds, int port,
@@ -1395,7 +1400,6 @@ static const struct dsa_switch_ops ksz9477_switch_ops = {
 	.port_fdb_dump		= ksz9477_port_fdb_dump,
 	.port_fdb_add		= ksz9477_port_fdb_add,
 	.port_fdb_del		= ksz9477_port_fdb_del,
-	.port_mdb_prepare       = ksz_port_mdb_prepare,
 	.port_mdb_add           = ksz9477_port_mdb_add,
 	.port_mdb_del           = ksz9477_port_mdb_del,
 	.port_mirror_add	= ksz9477_port_mirror_add,

drivers/net/dsa/microchip/ksz_common.c

@@ -253,15 +253,7 @@ int ksz_port_fdb_dump(struct dsa_switch *ds, int port, dsa_fdb_dump_cb_t *cb,
 }
 EXPORT_SYMBOL_GPL(ksz_port_fdb_dump);
 
-int ksz_port_mdb_prepare(struct dsa_switch *ds, int port,
-			 const struct switchdev_obj_port_mdb *mdb)
-{
-	/* nothing to do */
-	return 0;
-}
-EXPORT_SYMBOL_GPL(ksz_port_mdb_prepare);
-
-void ksz_port_mdb_add(struct dsa_switch *ds, int port,
+int ksz_port_mdb_add(struct dsa_switch *ds, int port,
 		     const struct switchdev_obj_port_mdb *mdb)
 {
 	struct ksz_device *dev = ds->priv;
@@ -284,7 +276,7 @@ void ksz_port_mdb_add(struct dsa_switch *ds, int port,
 
 	/* no available entry */
 	if (index == dev->num_statics && !empty)
-		return;
+		return -ENOSPC;
 
 	/* add entry */
 	if (index == dev->num_statics) {
@@ -301,6 +293,8 @@ void ksz_port_mdb_add(struct dsa_switch *ds, int port,
 		alu.fid = mdb->vid;
 	}
 	dev->dev_ops->w_sta_mac_table(dev, index, &alu);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(ksz_port_mdb_add);
 

drivers/net/dsa/microchip/ksz_common.h

@@ -165,9 +165,7 @@ int ksz_port_vlan_prepare(struct dsa_switch *ds, int port,
 			  const struct switchdev_obj_port_vlan *vlan);
 int ksz_port_fdb_dump(struct dsa_switch *ds, int port, dsa_fdb_dump_cb_t *cb,
 		      void *data);
-int ksz_port_mdb_prepare(struct dsa_switch *ds, int port,
-			 const struct switchdev_obj_port_mdb *mdb);
-void ksz_port_mdb_add(struct dsa_switch *ds, int port,
+int ksz_port_mdb_add(struct dsa_switch *ds, int port,
 		     const struct switchdev_obj_port_mdb *mdb);
 int ksz_port_mdb_del(struct dsa_switch *ds, int port,
 		     const struct switchdev_obj_port_mdb *mdb);

drivers/net/dsa/mv88e6xxx/chip.c

@@ -5238,27 +5238,18 @@ static enum dsa_tag_protocol mv88e6xxx_get_tag_protocol(struct dsa_switch *ds,
 	return chip->info->tag_protocol;
 }
 
-static int mv88e6xxx_port_mdb_prepare(struct dsa_switch *ds, int port,
-				      const struct switchdev_obj_port_mdb *mdb)
-{
-	/* We don't need any dynamic resource from the kernel (yet),
-	 * so skip the prepare phase.
-	 */
-
-	return 0;
-}
-
-static void mv88e6xxx_port_mdb_add(struct dsa_switch *ds, int port,
+static int mv88e6xxx_port_mdb_add(struct dsa_switch *ds, int port,
 				  const struct switchdev_obj_port_mdb *mdb)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
+	int err;
 
 	mv88e6xxx_reg_lock(chip);
-	if (mv88e6xxx_port_db_load_purge(chip, port, mdb->addr, mdb->vid,
-					 MV88E6XXX_G1_ATU_DATA_STATE_MC_STATIC))
-		dev_err(ds->dev, "p%d: failed to load multicast MAC address\n",
-			port);
+	err = mv88e6xxx_port_db_load_purge(chip, port, mdb->addr, mdb->vid,
+					   MV88E6XXX_G1_ATU_DATA_STATE_MC_STATIC);
 	mv88e6xxx_reg_unlock(chip);
+
+	return err;
 }
 
 static int mv88e6xxx_port_mdb_del(struct dsa_switch *ds, int port,
@@ -5403,7 +5394,6 @@ static const struct dsa_switch_ops mv88e6xxx_switch_ops = {
 	.port_fdb_add           = mv88e6xxx_port_fdb_add,
 	.port_fdb_del           = mv88e6xxx_port_fdb_del,
 	.port_fdb_dump          = mv88e6xxx_port_fdb_dump,
-	.port_mdb_prepare       = mv88e6xxx_port_mdb_prepare,
 	.port_mdb_add           = mv88e6xxx_port_mdb_add,
 	.port_mdb_del           = mv88e6xxx_port_mdb_del,
 	.port_mirror_add	= mv88e6xxx_port_mirror_add,

drivers/net/dsa/ocelot/felix.c

@@ -65,19 +65,12 @@ static int felix_fdb_del(struct dsa_switch *ds, int port,
 	return ocelot_fdb_del(ocelot, port, addr, vid);
 }
 
-/* This callback needs to be present */
-static int felix_mdb_prepare(struct dsa_switch *ds, int port,
-			     const struct switchdev_obj_port_mdb *mdb)
-{
-	return 0;
-}
-
-static void felix_mdb_add(struct dsa_switch *ds, int port,
+static int felix_mdb_add(struct dsa_switch *ds, int port,
 			 const struct switchdev_obj_port_mdb *mdb)
 {
 	struct ocelot *ocelot = ds->priv;
 
-	ocelot_port_mdb_add(ocelot, port, mdb);
+	return ocelot_port_mdb_add(ocelot, port, mdb);
 }
 
 static int felix_mdb_del(struct dsa_switch *ds, int port,
@@ -772,7 +765,6 @@ const struct dsa_switch_ops felix_switch_ops = {
 	.port_fdb_dump		= felix_fdb_dump,
 	.port_fdb_add		= felix_fdb_add,
 	.port_fdb_del		= felix_fdb_del,
-	.port_mdb_prepare	= felix_mdb_prepare,
 	.port_mdb_add		= felix_mdb_add,
 	.port_mdb_del		= felix_mdb_del,
 	.port_bridge_join	= felix_bridge_join,

drivers/net/dsa/sja1105/sja1105_main.c

@@ -1524,17 +1524,10 @@ static int sja1105_fdb_dump(struct dsa_switch *ds, int port,
 	return 0;
 }
 
-/* This callback needs to be present */
-static int sja1105_mdb_prepare(struct dsa_switch *ds, int port,
+static int sja1105_mdb_add(struct dsa_switch *ds, int port,
 			   const struct switchdev_obj_port_mdb *mdb)
 {
-	return 0;
-}
-
-static void sja1105_mdb_add(struct dsa_switch *ds, int port,
-			    const struct switchdev_obj_port_mdb *mdb)
-{
-	sja1105_fdb_add(ds, port, mdb->addr, mdb->vid);
+	return sja1105_fdb_add(ds, port, mdb->addr, mdb->vid);
 }
 
 static int sja1105_mdb_del(struct dsa_switch *ds, int port,
@@ -3288,7 +3281,6 @@ static const struct dsa_switch_ops sja1105_switch_ops = {
 	.port_vlan_filtering	= sja1105_vlan_filtering,
 	.port_vlan_add		= sja1105_vlan_add,
 	.port_vlan_del		= sja1105_vlan_del,
-	.port_mdb_prepare	= sja1105_mdb_prepare,
 	.port_mdb_add		= sja1105_mdb_add,
 	.port_mdb_del		= sja1105_mdb_del,
 	.port_hwtstamp_get	= sja1105_hwtstamp_get,

include/net/dsa.h

@@ -585,9 +585,7 @@ struct dsa_switch_ops {
 	/*
 	 * Multicast database
 	 */
-	int (*port_mdb_prepare)(struct dsa_switch *ds, int port,
-				const struct switchdev_obj_port_mdb *mdb);
-	void (*port_mdb_add)(struct dsa_switch *ds, int port,
+	int	(*port_mdb_add)(struct dsa_switch *ds, int port,
 				const struct switchdev_obj_port_mdb *mdb);
 	int	(*port_mdb_del)(struct dsa_switch *ds, int port,
 				const struct switchdev_obj_port_mdb *mdb);

net/dsa/switch.c

@@ -181,24 +181,21 @@ static bool dsa_switch_mdb_match(struct dsa_switch *ds, int port,
 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;
 		}
 	}
 
-	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,