ocelot: Dont allocate another multicast list, use __dev_mc_sync

Doing kmalloc in atomic context is always an issue,
more so for a list that can grow significantly.
Turns out that the driver only uses the duplicated
list of multicast mac addresses to keep track of
what addresses to delete from h/w before committing
the new list from kernel to h/w back again via set_rx_mode,
every time this list gets updated by the kernel.
Given that the h/w knows how to add and delete mac addresses
based on the mac address value alone, __dev_mc_sync should be
the much better choice of kernel API for these operations
avoiding the considerable overhead of maintaining a duplicated
list in the driver.

Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index d715ef4..02ad11e 100644 (file)
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -593,45 +593,25 @@ static int ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
        return NETDEV_TX_OK;
 }
 
-static void ocelot_mact_mc_reset(struct ocelot_port *port)
+static int ocelot_mc_unsync(struct net_device *dev, const unsigned char *addr)
 {
-       struct ocelot *ocelot = port->ocelot;
-       struct netdev_hw_addr *ha, *n;
+       struct ocelot_port *port = netdev_priv(dev);
 
-       /* Free and forget all the MAC addresses stored in the port private mc
-        * list. These are mc addresses that were previously added by calling
-        * ocelot_mact_mc_add().
-        */
-       list_for_each_entry_safe(ha, n, &port->mc, list) {
-               ocelot_mact_forget(ocelot, ha->addr, port->pvid);
-               list_del(&ha->list);
-               kfree(ha);
-       }
+       return ocelot_mact_forget(port->ocelot, addr, port->pvid);
 }
 
-static int ocelot_mact_mc_add(struct ocelot_port *port,
-                             struct netdev_hw_addr *hw_addr)
+static int ocelot_mc_sync(struct net_device *dev, const unsigned char *addr)
 {
-       struct ocelot *ocelot = port->ocelot;
-       struct netdev_hw_addr *ha = kzalloc(sizeof(*ha), GFP_ATOMIC);
-
-       if (!ha)
-               return -ENOMEM;
-
-       memcpy(ha, hw_addr, sizeof(*ha));
-       list_add_tail(&ha->list, &port->mc);
-
-       ocelot_mact_learn(ocelot, PGID_CPU, ha->addr, port->pvid,
-                         ENTRYTYPE_LOCKED);
+       struct ocelot_port *port = netdev_priv(dev);
 
-       return 0;
+       return ocelot_mact_learn(port->ocelot, PGID_CPU, addr, port->pvid,
+                                ENTRYTYPE_LOCKED);
 }
 
 static void ocelot_set_rx_mode(struct net_device *dev)
 {
        struct ocelot_port *port = netdev_priv(dev);
        struct ocelot *ocelot = port->ocelot;
-       struct netdev_hw_addr *ha;
        int i;
        u32 val;
 
@@ -643,13 +623,7 @@ static void ocelot_set_rx_mode(struct net_device *dev)
        for (i = ocelot->num_phys_ports + 1; i < PGID_CPU; i++)
                ocelot_write_rix(ocelot, val, ANA_PGID_PGID, i);
 
-       /* Handle the device multicast addresses. First remove all the
-        * previously installed addresses and then add the latest ones to the
-        * mac table.
-        */
-       ocelot_mact_mc_reset(port);
-       netdev_for_each_mc_addr(ha, dev)
-               ocelot_mact_mc_add(port, ha);
+       __dev_mc_sync(dev, ocelot_mc_sync, ocelot_mc_unsync);
 }
 
 static int ocelot_port_get_phys_port_name(struct net_device *dev,
@@ -1657,7 +1631,6 @@ int ocelot_probe_port(struct ocelot *ocelot, u8 port,
        ocelot_port->regs = regs;
        ocelot_port->chip_port = port;
        ocelot_port->phy = phy;
-       INIT_LIST_HEAD(&ocelot_port->mc);
        ocelot->ports[port] = ocelot_port;
 
        dev->netdev_ops = &ocelot_port_netdev_ops;

diff --git a/drivers/net/ethernet/mscc/ocelot.h b/drivers/net/ethernet/mscc/ocelot.h
index ba3b338..541fe41 100644 (file)
--- a/drivers/net/ethernet/mscc/ocelot.h
+++ b/drivers/net/ethernet/mscc/ocelot.h
@@ -441,10 +441,6 @@ struct ocelot_port {
        struct phy_device *phy;
        void __iomem *regs;
        u8 chip_port;
-       /* Keep a track of the mc addresses added to the mac table, so that they
-        * can be removed when needed.
-        */
-       struct list_head mc;
 
        /* Ingress default VLAN (pvid) */
        u16 pvid;