net: dsa: mv88e6xxx: handle multiple ports in ATU

An address can be loaded in the ATU with multiple ports, for instance
when adding multiple ports to a Multicast group with "bridge mdb".

The current code doesn't allow that. Add an helper to get a single entry
from the ATU, then set or clear the requested port, before loading the
entry back in the ATU.

Note that the required _mv88e6xxx_atu_getnext function is defined below
mv88e6xxx_port_db_load_purge, so forward-declare it for the moment. The
ATU code will be isolated in future patches.

Fixes: 83dabd1fa84c ("net: dsa: mv88e6xxx: make switchdev DB ops generic")
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 70a812d..1d71802 100644 (file)
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -2091,12 +2091,48 @@ static int _mv88e6xxx_atu_load(struct mv88e6xxx_chip *chip,
        return _mv88e6xxx_atu_cmd(chip, entry->fid, GLOBAL_ATU_OP_LOAD_DB);
 }
 
+static int _mv88e6xxx_atu_getnext(struct mv88e6xxx_chip *chip, u16 fid,
+                                 struct mv88e6xxx_atu_entry *entry);
+
+static int mv88e6xxx_atu_get(struct mv88e6xxx_chip *chip, int fid,
+                            const u8 *addr, struct mv88e6xxx_atu_entry *entry)
+{
+       struct mv88e6xxx_atu_entry next;
+       int err;
+
+       eth_broadcast_addr(next.mac);
+
+       err = _mv88e6xxx_atu_mac_write(chip, next.mac);
+       if (err)
+               return err;
+
+       do {
+               err = _mv88e6xxx_atu_getnext(chip, fid, &next);
+               if (err)
+                       return err;
+
+               if (next.state == GLOBAL_ATU_DATA_STATE_UNUSED)
+                       break;
+
+               if (ether_addr_equal(next.mac, addr)) {
+                       *entry = next;
+                       return 0;
+               }
+       } while (!is_broadcast_ether_addr(next.mac));
+
+       memset(entry, 0, sizeof(*entry));
+       entry->fid = fid;
+       ether_addr_copy(entry->mac, addr);
+
+       return 0;
+}
+
 static int mv88e6xxx_port_db_load_purge(struct mv88e6xxx_chip *chip, int port,
                                        const unsigned char *addr, u16 vid,
                                        u8 state)
 {
-       struct mv88e6xxx_atu_entry entry = { 0 };
        struct mv88e6xxx_vtu_stu_entry vlan;
+       struct mv88e6xxx_atu_entry entry;
        int err;
 
        /* Null VLAN ID corresponds to the port private database */
@@ -2107,12 +2143,18 @@ static int mv88e6xxx_port_db_load_purge(struct mv88e6xxx_chip *chip, int port,
        if (err)
                return err;
 
-       entry.fid = vlan.fid;
-       entry.state = state;
-       ether_addr_copy(entry.mac, addr);
-       if (state != GLOBAL_ATU_DATA_STATE_UNUSED) {
-               entry.trunk = false;
-               entry.portv_trunkid = BIT(port);
+       err = mv88e6xxx_atu_get(chip, vlan.fid, addr, &entry);
+       if (err)
+               return err;
+
+       /* Purge the ATU entry only if no port is using it anymore */
+       if (state == GLOBAL_ATU_DATA_STATE_UNUSED) {
+               entry.portv_trunkid &= ~BIT(port);
+               if (!entry.portv_trunkid)
+                       entry.state = GLOBAL_ATU_DATA_STATE_UNUSED;
+       } else {
+               entry.portv_trunkid |= BIT(port);
+               entry.state = state;
        }
 
        return _mv88e6xxx_atu_load(chip, &entry);