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>

4 files changed, 16 insertions, 21 deletions

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 6a9ec8a0f92f..89e1c01cf5b8 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/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,
diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c
index 446c088ce5c5..08bf54eb9f5f 100644
--- a/drivers/net/dsa/microchip/ksz9477.c
+++ b/drivers/net/dsa/microchip/ksz9477.c
@@ -774,14 +774,15 @@ exit:
 	return ret;
 }
 
-static void ksz9477_port_mdb_add(struct dsa_switch *ds, int port,
-				 const struct switchdev_obj_port_mdb *mdb)
+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;
 	u32 static_table[4];
 	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,
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index cf743133b0b9..f2c9ff3ea4be 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -253,16 +253,8 @@ 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,
-		      const struct switchdev_obj_port_mdb *mdb)
+int ksz_port_mdb_add(struct dsa_switch *ds, int port,
+		     const struct switchdev_obj_port_mdb *mdb)
 {
 	struct ksz_device *dev = ds->priv;
 	struct alu_struct alu;
@@ -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);
 
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 720f22275c84..a1f0929d45a0 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -165,10 +165,8 @@ 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,
-		      const struct switchdev_obj_port_mdb *mdb);
+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);
 int ksz_enable_port(struct dsa_switch *ds, int port, struct phy_device *phy);