net: dsa: create a dsa_lag structure

The main purpose of this change is to create a data structure for a LAG
as seen by DSA. This is similar to what we have for bridging - we pass a
copy of this structure by value to ->port_lag_join and ->port_lag_leave.
For now we keep the lag_dev, id and a reference count in it. Future
patches will add a list of FDB entries for the LAG (these also need to
be refcounted to work properly).

The LAG structure is created using dsa_port_lag_create() and destroyed
using dsa_port_lag_destroy(), just like we have for bridging.

Because now, the dsa_lag itself is refcounted, we can simplify
dsa_lag_map() and dsa_lag_unmap(). These functions need to keep a LAG in
the dst->lags array only as long as at least one port uses it. The
refcounting logic inside those functions can be removed now - they are
called only when we should perform the operation.

dsa_lag_dev() is renamed to dsa_lag_by_id() and now returns the dsa_lag
structure instead of the lag_dev net_device.

dsa_lag_foreach_port() now takes the dsa_lag structure as argument.

dst->lags holds an array of dsa_lag structures.

dsa_lag_map() now also saves the dsa_lag->id value, so that linear
walking of dst->lags in drivers using dsa_lag_id() is no longer
necessary. They can just look at lag.id.

dsa_port_lag_id_get() is a helper, similar to dsa_port_bridge_num_get(),
which can be used by drivers to get the LAG ID assigned by DSA to a
given port.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 49 insertions, 56 deletions

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 8868110fcc9c..1b9a20bf1bd6 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -1625,7 +1625,7 @@ static int mv88e6xxx_pvt_map(struct mv88e6xxx_chip *chip, int dev, int port)
 
 		ds = dsa_switch_find(dst->index, dev);
 		dp = ds ? dsa_to_port(ds, port) : NULL;
-		if (dp && dp->lag_dev) {
+		if (dp && dp->lag) {
 			/* As the PVT is used to limit flooding of
 			 * FORWARD frames, which use the LAG ID as the
 			 * source port, we must translate dev/port to
@@ -1634,7 +1634,7 @@ static int mv88e6xxx_pvt_map(struct mv88e6xxx_chip *chip, int dev, int port)
 			 * (zero-based).
 			 */
 			dev = MV88E6XXX_G2_PVT_ADDR_DEV_TRUNK;
-			port = dsa_lag_id(dst, dp->lag_dev) - 1;
+			port = dsa_port_lag_id_get(dp) - 1;
 		}
 	}
 
@@ -1672,7 +1672,7 @@ static void mv88e6xxx_port_fast_age(struct dsa_switch *ds, int port)
 	struct mv88e6xxx_chip *chip = ds->priv;
 	int err;
 
-	if (dsa_to_port(ds, port)->lag_dev)
+	if (dsa_to_port(ds, port)->lag)
 		/* Hardware is incapable of fast-aging a LAG through a
 		 * regular ATU move operation. Until we have something
 		 * more fancy in place this is a no-op.
@@ -6176,21 +6176,20 @@ out:
 }
 
 static bool mv88e6xxx_lag_can_offload(struct dsa_switch *ds,
-				      struct net_device *lag_dev,
+				      struct dsa_lag lag,
 				      struct netdev_lag_upper_info *info)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 	struct dsa_port *dp;
-	int id, members = 0;
+	int members = 0;
 
 	if (!mv88e6xxx_has_lag(chip))
 		return false;
 
-	id = dsa_lag_id(ds->dst, lag_dev);
-	if (id <= 0 || id > ds->num_lag_ids)
+	if (!lag.id)
 		return false;
 
-	dsa_lag_foreach_port(dp, ds->dst, lag_dev)
+	dsa_lag_foreach_port(dp, ds->dst, &lag)
 		/* Includes the port joining the LAG */
 		members++;
 
@@ -6210,8 +6209,7 @@ static bool mv88e6xxx_lag_can_offload(struct dsa_switch *ds,
 	return true;
 }
 
-static int mv88e6xxx_lag_sync_map(struct dsa_switch *ds,
-				  struct net_device *lag_dev)
+static int mv88e6xxx_lag_sync_map(struct dsa_switch *ds, struct dsa_lag lag)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 	struct dsa_port *dp;
@@ -6219,13 +6217,13 @@ static int mv88e6xxx_lag_sync_map(struct dsa_switch *ds,
 	int id;
 
 	/* DSA LAG IDs are one-based, hardware is zero-based */
-	id = dsa_lag_id(ds->dst, lag_dev) - 1;
+	id = lag.id - 1;
 
 	/* Build the map of all ports to distribute flows destined for
 	 * this LAG. This can be either a local user port, or a DSA
 	 * port if the LAG port is on a remote chip.
 	 */
-	dsa_lag_foreach_port(dp, ds->dst, lag_dev)
+	dsa_lag_foreach_port(dp, ds->dst, &lag)
 		map |= BIT(dsa_towards_port(ds, dp->ds->index, dp->index));
 
 	return mv88e6xxx_g2_trunk_mapping_write(chip, id, map);
@@ -6269,9 +6267,9 @@ static void mv88e6xxx_lag_set_port_mask(u16 *mask, int port,
 static int mv88e6xxx_lag_sync_masks(struct dsa_switch *ds)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
-	struct net_device *lag_dev;
 	unsigned int id, num_tx;
 	struct dsa_port *dp;
+	struct dsa_lag *lag;
 	int i, err, nth;
 	u16 mask[8];
 	u16 ivec;
@@ -6281,7 +6279,7 @@ static int mv88e6xxx_lag_sync_masks(struct dsa_switch *ds)
 
 	/* Disable all masks for ports that _are_ members of a LAG. */
 	dsa_switch_for_each_port(dp, ds) {
-		if (!dp->lag_dev)
+		if (!dp->lag)
 			continue;
 
 		ivec &= ~BIT(dp->index);
@@ -6294,12 +6292,12 @@ static int mv88e6xxx_lag_sync_masks(struct dsa_switch *ds)
 	 * are in the Tx set.
 	 */
 	dsa_lags_foreach_id(id, ds->dst) {
-		lag_dev = dsa_lag_dev(ds->dst, id);
-		if (!lag_dev)
+		lag = dsa_lag_by_id(ds->dst, id);
+		if (!lag)
 			continue;
 
 		num_tx = 0;
-		dsa_lag_foreach_port(dp, ds->dst, lag_dev) {
+		dsa_lag_foreach_port(dp, ds->dst, lag) {
 			if (dp->lag_tx_enabled)
 				num_tx++;
 		}
@@ -6308,7 +6306,7 @@ static int mv88e6xxx_lag_sync_masks(struct dsa_switch *ds)
 			continue;
 
 		nth = 0;
-		dsa_lag_foreach_port(dp, ds->dst, lag_dev) {
+		dsa_lag_foreach_port(dp, ds->dst, lag) {
 			if (!dp->lag_tx_enabled)
 				continue;
 
@@ -6330,14 +6328,14 @@ static int mv88e6xxx_lag_sync_masks(struct dsa_switch *ds)
 }
 
 static int mv88e6xxx_lag_sync_masks_map(struct dsa_switch *ds,
-					struct net_device *lag_dev)
+					struct dsa_lag lag)
 {
 	int err;
 
 	err = mv88e6xxx_lag_sync_masks(ds);
 
 	if (!err)
-		err = mv88e6xxx_lag_sync_map(ds, lag_dev);
+		err = mv88e6xxx_lag_sync_map(ds, lag);
 
 	return err;
 }
@@ -6354,17 +6352,17 @@ static int mv88e6xxx_port_lag_change(struct dsa_switch *ds, int port)
 }
 
 static int mv88e6xxx_port_lag_join(struct dsa_switch *ds, int port,
-				   struct net_device *lag_dev,
+				   struct dsa_lag lag,
 				   struct netdev_lag_upper_info *info)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 	int err, id;
 
-	if (!mv88e6xxx_lag_can_offload(ds, lag_dev, info))
+	if (!mv88e6xxx_lag_can_offload(ds, lag, info))
 		return -EOPNOTSUPP;
 
 	/* DSA LAG IDs are one-based */
-	id = dsa_lag_id(ds->dst, lag_dev) - 1;
+	id = lag.id - 1;
 
 	mv88e6xxx_reg_lock(chip);
 
@@ -6372,7 +6370,7 @@ static int mv88e6xxx_port_lag_join(struct dsa_switch *ds, int port,
 	if (err)
 		goto err_unlock;
 
-	err = mv88e6xxx_lag_sync_masks_map(ds, lag_dev);
+	err = mv88e6xxx_lag_sync_masks_map(ds, lag);
 	if (err)
 		goto err_clear_trunk;
 
@@ -6387,13 +6385,13 @@ err_unlock:
 }
 
 static int mv88e6xxx_port_lag_leave(struct dsa_switch *ds, int port,
-				    struct net_device *lag_dev)
+				    struct dsa_lag lag)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 	int err_sync, err_trunk;
 
 	mv88e6xxx_reg_lock(chip);
-	err_sync = mv88e6xxx_lag_sync_masks_map(ds, lag_dev);
+	err_sync = mv88e6xxx_lag_sync_masks_map(ds, lag);
 	err_trunk = mv88e6xxx_port_set_trunk(chip, port, false, 0);
 	mv88e6xxx_reg_unlock(chip);
 	return err_sync ? : err_trunk;
@@ -6412,18 +6410,18 @@ static int mv88e6xxx_crosschip_lag_change(struct dsa_switch *ds, int sw_index,
 }
 
 static int mv88e6xxx_crosschip_lag_join(struct dsa_switch *ds, int sw_index,
-					int port, struct net_device *lag_dev,
+					int port, struct dsa_lag lag,
 					struct netdev_lag_upper_info *info)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 	int err;
 
-	if (!mv88e6xxx_lag_can_offload(ds, lag_dev, info))
+	if (!mv88e6xxx_lag_can_offload(ds, lag, info))
 		return -EOPNOTSUPP;
 
 	mv88e6xxx_reg_lock(chip);
 
-	err = mv88e6xxx_lag_sync_masks_map(ds, lag_dev);
+	err = mv88e6xxx_lag_sync_masks_map(ds, lag);
 	if (err)
 		goto unlock;
 
@@ -6435,13 +6433,13 @@ unlock:
 }
 
 static int mv88e6xxx_crosschip_lag_leave(struct dsa_switch *ds, int sw_index,
-					 int port, struct net_device *lag_dev)
+					 int port, struct dsa_lag lag)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 	int err_sync, err_pvt;
 
 	mv88e6xxx_reg_lock(chip);
-	err_sync = mv88e6xxx_lag_sync_masks_map(ds, lag_dev);
+	err_sync = mv88e6xxx_lag_sync_masks_map(ds, lag);
 	err_pvt = mv88e6xxx_pvt_map(chip, sw_index, port);
 	mv88e6xxx_reg_unlock(chip);
 	return err_sync ? : err_pvt;
diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index 9ffd5491bf2d..6d483887af04 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -677,20 +677,20 @@ static void felix_bridge_leave(struct dsa_switch *ds, int port,
 }
 
 static int felix_lag_join(struct dsa_switch *ds, int port,
-			  struct net_device *bond,
+			  struct dsa_lag lag,
 			  struct netdev_lag_upper_info *info)
 {
 	struct ocelot *ocelot = ds->priv;
 
-	return ocelot_port_lag_join(ocelot, port, bond, info);
+	return ocelot_port_lag_join(ocelot, port, lag.dev, info);
 }
 
 static int felix_lag_leave(struct dsa_switch *ds, int port,
-			   struct net_device *bond)
+			   struct dsa_lag lag)
 {
 	struct ocelot *ocelot = ds->priv;
 
-	ocelot_port_lag_leave(ocelot, port, bond);
+	ocelot_port_lag_leave(ocelot, port, lag.dev);
 
 	return 0;
 }
diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index ed55e9357c2b..6844106975a9 100644
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -2646,18 +2646,16 @@ qca8k_get_tag_protocol(struct dsa_switch *ds, int port,
 }
 
 static bool
-qca8k_lag_can_offload(struct dsa_switch *ds,
-		      struct net_device *lag_dev,
+qca8k_lag_can_offload(struct dsa_switch *ds, struct dsa_lag lag,
 		      struct netdev_lag_upper_info *info)
 {
 	struct dsa_port *dp;
-	int id, members = 0;
+	int members = 0;
 
-	id = dsa_lag_id(ds->dst, lag_dev);
-	if (id <= 0 || id > ds->num_lag_ids)
+	if (!lag.id)
 		return false;
 
-	dsa_lag_foreach_port(dp, ds->dst, lag_dev)
+	dsa_lag_foreach_port(dp, ds->dst, &lag)
 		/* Includes the port joining the LAG */
 		members++;
 
@@ -2675,16 +2673,14 @@ qca8k_lag_can_offload(struct dsa_switch *ds,
 }
 
 static int
-qca8k_lag_setup_hash(struct dsa_switch *ds,
-		     struct net_device *lag_dev,
+qca8k_lag_setup_hash(struct dsa_switch *ds, struct dsa_lag lag,
 		     struct netdev_lag_upper_info *info)
 {
+	struct net_device *lag_dev = lag.dev;
 	struct qca8k_priv *priv = ds->priv;
 	bool unique_lag = true;
+	unsigned int i;
 	u32 hash = 0;
-	int i, id;
-
-	id = dsa_lag_id(ds->dst, lag_dev);
 
 	switch (info->hash_type) {
 	case NETDEV_LAG_HASH_L23:
@@ -2701,7 +2697,7 @@ qca8k_lag_setup_hash(struct dsa_switch *ds,
 
 	/* Check if we are the unique configured LAG */
 	dsa_lags_foreach_id(i, ds->dst)
-		if (i != id && dsa_lag_dev(ds->dst, i)) {
+		if (i != lag.id && dsa_lag_by_id(ds->dst, i)) {
 			unique_lag = false;
 			break;
 		}
@@ -2726,14 +2722,14 @@ qca8k_lag_setup_hash(struct dsa_switch *ds,
 
 static int
 qca8k_lag_refresh_portmap(struct dsa_switch *ds, int port,
-			  struct net_device *lag_dev, bool delete)
+			  struct dsa_lag lag, bool delete)
 {
 	struct qca8k_priv *priv = ds->priv;
 	int ret, id, i;
 	u32 val;
 
 	/* DSA LAG IDs are one-based, hardware is zero-based */
-	id = dsa_lag_id(ds->dst, lag_dev) - 1;
+	id = lag.id - 1;
 
 	/* Read current port member */
 	ret = regmap_read(priv->regmap, QCA8K_REG_GOL_TRUNK_CTRL0, &val);
@@ -2795,27 +2791,26 @@ qca8k_lag_refresh_portmap(struct dsa_switch *ds, int port,
 }
 
 static int
-qca8k_port_lag_join(struct dsa_switch *ds, int port,
-		    struct net_device *lag_dev,
+qca8k_port_lag_join(struct dsa_switch *ds, int port, struct dsa_lag lag,
 		    struct netdev_lag_upper_info *info)
 {
 	int ret;
 
-	if (!qca8k_lag_can_offload(ds, lag_dev, info))
+	if (!qca8k_lag_can_offload(ds, lag, info))
 		return -EOPNOTSUPP;
 
-	ret = qca8k_lag_setup_hash(ds, lag_dev, info);
+	ret = qca8k_lag_setup_hash(ds, lag, info);
 	if (ret)
 		return ret;
 
-	return qca8k_lag_refresh_portmap(ds, port, lag_dev, false);
+	return qca8k_lag_refresh_portmap(ds, port, lag, false);
 }
 
 static int
 qca8k_port_lag_leave(struct dsa_switch *ds, int port,
-		     struct net_device *lag_dev)
+		     struct dsa_lag lag)
 {
-	return qca8k_lag_refresh_portmap(ds, port, lag_dev, true);
+	return qca8k_lag_refresh_portmap(ds, port, lag, true);
 }
 
 static void