net: sparx5: Refactor mdb handling according to feedback

- Remove mact_lookup and use new mact_find instead.
- Make pgid_read_mask function.
- Set PGID arbiter to start searching at PGID_BASE + 8.

This is according to feedback on previous patch.
https://lore.kernel.org/netdev/20220322081823.wqbx7vud4q7qtjuq@wse-c0155/T/#tSigned-off-by: Casper Andersson <casper.casan@gmail.com>
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/microchip/sparx5/sparx5_mactable.c

@@ -212,19 +212,7 @@ bool sparx5_mact_find(struct sparx5 *sparx5,
 
 	mutex_unlock(&sparx5->lock);
 
-	return ret == 0;
-}
-
-static int sparx5_mact_lookup(struct sparx5 *sparx5,
-			      const unsigned char mac[ETH_ALEN],
-			      u16 vid)
-{
-	u32 pcfg2;
-
-	if (sparx5_mact_find(sparx5, mac, vid, &pcfg2))
-		return 1;
-
-	return 0;
+	return ret;
 }
 
 int sparx5_mact_forget(struct sparx5 *sparx5,
@@ -305,9 +293,10 @@ int sparx5_add_mact_entry(struct sparx5 *sparx5,
 {
 	struct sparx5_mact_entry *mact_entry;
 	int ret;
+	u32 cfg2;
 
-	ret = sparx5_mact_lookup(sparx5, addr, vid);
-	if (ret)
+	ret = sparx5_mact_find(sparx5, addr, vid, &cfg2);
+	if (!ret)
 		return 0;
 
 	/* In case the entry already exists, don't add it again to SW,

drivers/net/ethernet/microchip/sparx5/sparx5_main.h

@@ -65,10 +65,10 @@ enum sparx5_vlan_port_type {
 #define PGID_IPV6_MC_CTRL      (PGID_BASE + 5)
 #define PGID_BCAST	       (PGID_BASE + 6)
 #define PGID_CPU	       (PGID_BASE + 7)
+#define PGID_MCAST_START       (PGID_BASE + 8)
 
 #define PGID_TABLE_SIZE	       3290
 
-#define PGID_MCAST_START 65
 #define IFH_LEN                9 /* 36 bytes */
 #define NULL_VID               0
 #define SPX5_MACT_PULL_DELAY   (2 * HZ)
@@ -325,6 +325,7 @@ void sparx5_mact_init(struct sparx5 *sparx5);
 
 /* sparx5_vlan.c */
 void sparx5_pgid_update_mask(struct sparx5_port *port, int pgid, bool enable);
+void sparx5_pgid_read_mask(struct sparx5 *sparx5, int pgid, u32 portmask[3]);
 void sparx5_update_fwd(struct sparx5 *sparx5);
 void sparx5_vlan_init(struct sparx5 *sparx5);
 void sparx5_vlan_port_setup(struct sparx5 *sparx5, int portno);

drivers/net/ethernet/microchip/sparx5/sparx5_pgid.c

@@ -19,6 +19,9 @@ int sparx5_pgid_alloc_mcast(struct sparx5 *spx5, u16 *idx)
 {
 	int i;
 
+	/* The multicast area starts at index 65, but the first 7
+	 * are reserved for flood masks and CPU. Start alloc after that.
+	 */
 	for (i = PGID_MCAST_START; i < PGID_TABLE_SIZE; i++) {
 		if (spx5->pgid_map[i] == SPX5_PGID_FREE) {
 			spx5->pgid_map[i] = SPX5_PGID_MULTICAST;

drivers/net/ethernet/microchip/sparx5/sparx5_switchdev.c

@@ -406,11 +406,11 @@ static int sparx5_handle_port_mdb_add(struct net_device *dev,
 
 	res = sparx5_mact_find(spx5, v->addr, vid, &mact_entry);
 
-	if (res) {
+	if (res == 0) {
 		pgid_idx = LRN_MAC_ACCESS_CFG_2_MAC_ENTRY_ADDR_GET(mact_entry);
 
-		/* MC_IDX has an offset of 65 in the PGID table. */
-		pgid_idx += PGID_MCAST_START;
+		/* MC_IDX starts after the port masks in the PGID table */
+		pgid_idx += SPX5_PORTS;
 		sparx5_pgid_update_mask(port, pgid_idx, true);
 	} else {
 		err = sparx5_pgid_alloc_mcast(spx5, &pgid_idx);
@@ -468,17 +468,15 @@ static int sparx5_handle_port_mdb_del(struct net_device *dev,
 
 	res = sparx5_mact_find(spx5, v->addr, vid, &mact_entry);
 
-	if (res) {
+	if (res == 0) {
 		pgid_idx = LRN_MAC_ACCESS_CFG_2_MAC_ENTRY_ADDR_GET(mact_entry);
 
-		/* MC_IDX has an offset of 65 in the PGID table. */
-		pgid_idx += PGID_MCAST_START;
+		/* MC_IDX starts after the port masks in the PGID table */
+		pgid_idx += SPX5_PORTS;
 		sparx5_pgid_update_mask(port, pgid_idx, false);
 
-		pgid_entry[0] = spx5_rd(spx5, ANA_AC_PGID_CFG(pgid_idx));
-		pgid_entry[1] = spx5_rd(spx5, ANA_AC_PGID_CFG1(pgid_idx));
-		pgid_entry[2] = spx5_rd(spx5, ANA_AC_PGID_CFG2(pgid_idx));
-		if (pgid_entry[0] == 0 && pgid_entry[1] == 0 && pgid_entry[2] == 0) {
+		sparx5_pgid_read_mask(spx5, pgid_idx, pgid_entry);
+		if (bitmap_empty((unsigned long *)pgid_entry, SPX5_PORTS)) {
 			/* No ports are in MC group. Remove entry */
 			err = sparx5_mdb_del_entry(dev, spx5, v->addr, vid, pgid_idx);
 			if (err)

drivers/net/ethernet/microchip/sparx5/sparx5_vlan.c

@@ -138,6 +138,13 @@ void sparx5_pgid_update_mask(struct sparx5_port *port, int pgid, bool enable)
 	}
 }
 
+void sparx5_pgid_read_mask(struct sparx5 *spx5, int pgid, u32 portmask[3])
+{
+	portmask[0] = spx5_rd(spx5, ANA_AC_PGID_CFG(pgid));
+	portmask[1] = spx5_rd(spx5, ANA_AC_PGID_CFG1(pgid));
+	portmask[2] = spx5_rd(spx5, ANA_AC_PGID_CFG2(pgid));
+}
+
 void sparx5_update_fwd(struct sparx5 *sparx5)
 {
 	DECLARE_BITMAP(workmask, SPX5_PORTS);