net: dpaa2-switch: serialize changes to priv->mac with a mutex

The dpaa2-switch driver uses a DPMAC in the same way as the dpaa2-eth
driver, so we need to duplicate the locking solution established by the
previous change to the switch driver as well.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch-ethtool.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch-ethtool.c
index 76a4b09e285436898dc7454d9c3d2eb58c7ca8b8..6bc1988be31122dbef2e12d41a326c1ab47f6f93 100644 (file)
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch-ethtool.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch-ethtool.c
@@ -60,11 +60,18 @@ dpaa2_switch_get_link_ksettings(struct net_device *netdev,
 {
        struct ethsw_port_priv *port_priv = netdev_priv(netdev);
        struct dpsw_link_state state = {0};
-       int err = 0;
+       int err;
+
+       mutex_lock(&port_priv->mac_lock);
 
-       if (dpaa2_switch_port_is_type_phy(port_priv))
-               return phylink_ethtool_ksettings_get(port_priv->mac->phylink,
-                                                    link_ksettings);
+       if (dpaa2_switch_port_is_type_phy(port_priv)) {
+               err = phylink_ethtool_ksettings_get(port_priv->mac->phylink,
+                                                   link_ksettings);
+               mutex_unlock(&port_priv->mac_lock);
+               return err;
+       }
+
+       mutex_unlock(&port_priv->mac_lock);
 
        err = dpsw_if_get_link_state(port_priv->ethsw_data->mc_io, 0,
                                     port_priv->ethsw_data->dpsw_handle,
@@ -99,9 +106,16 @@ dpaa2_switch_set_link_ksettings(struct net_device *netdev,
        bool if_running;
        int err = 0, ret;
 
-       if (dpaa2_switch_port_is_type_phy(port_priv))
-               return phylink_ethtool_ksettings_set(port_priv->mac->phylink,
-                                                    link_ksettings);
+       mutex_lock(&port_priv->mac_lock);
+
+       if (dpaa2_switch_port_is_type_phy(port_priv)) {
+               err = phylink_ethtool_ksettings_set(port_priv->mac->phylink,
+                                                   link_ksettings);
+               mutex_unlock(&port_priv->mac_lock);
+               return err;
+       }
+
+       mutex_unlock(&port_priv->mac_lock);
 
        /* Interface needs to be down to change link settings */
        if_running = netif_running(netdev);
@@ -189,8 +203,12 @@ static void dpaa2_switch_ethtool_get_stats(struct net_device *netdev,
                                   dpaa2_switch_ethtool_counters[i].name, err);
        }
 
+       mutex_lock(&port_priv->mac_lock);
+
        if (dpaa2_switch_port_has_mac(port_priv))
                dpaa2_mac_get_ethtool_stats(port_priv->mac, data + i);
+
+       mutex_unlock(&port_priv->mac_lock);
 }
 
 const struct ethtool_ops dpaa2_switch_port_ethtool_ops = {

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
index 3b0963d95f6778baed3bc726cd37da5c6038f973..0472e24191ad85d75668cdf2df9e14ad8c5c899f 100644 (file)
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
@@ -602,8 +602,11 @@ static int dpaa2_switch_port_link_state_update(struct net_device *netdev)
 
        /* When we manage the MAC/PHY using phylink there is no need
         * to manually update the netif_carrier.
+        * We can avoid locking because we are called from the "link changed"
+        * IRQ handler, which is the same as the "endpoint changed" IRQ handler
+        * (the writer to port_priv->mac), so we cannot race with it.
         */
-       if (dpaa2_switch_port_is_type_phy(port_priv))
+       if (dpaa2_mac_is_type_phy(port_priv->mac))
                return 0;
 
        /* Interrupts are received even though no one issued an 'ifconfig up'
@@ -683,6 +686,8 @@ static int dpaa2_switch_port_open(struct net_device *netdev)
        struct ethsw_core *ethsw = port_priv->ethsw_data;
        int err;
 
+       mutex_lock(&port_priv->mac_lock);
+
        if (!dpaa2_switch_port_is_type_phy(port_priv)) {
                /* Explicitly set carrier off, otherwise
                 * netif_carrier_ok() will return true and cause 'ip link show'
@@ -696,6 +701,7 @@ static int dpaa2_switch_port_open(struct net_device *netdev)
                             port_priv->ethsw_data->dpsw_handle,
                             port_priv->idx);
        if (err) {
+               mutex_unlock(&port_priv->mac_lock);
                netdev_err(netdev, "dpsw_if_enable err %d\n", err);
                return err;
        }
@@ -705,6 +711,8 @@ static int dpaa2_switch_port_open(struct net_device *netdev)
        if (dpaa2_switch_port_is_type_phy(port_priv))
                dpaa2_mac_start(port_priv->mac);
 
+       mutex_unlock(&port_priv->mac_lock);
+
        return 0;
 }
 
@@ -714,6 +722,8 @@ static int dpaa2_switch_port_stop(struct net_device *netdev)
        struct ethsw_core *ethsw = port_priv->ethsw_data;
        int err;
 
+       mutex_lock(&port_priv->mac_lock);
+
        if (dpaa2_switch_port_is_type_phy(port_priv)) {
                dpaa2_mac_stop(port_priv->mac);
        } else {
@@ -721,6 +731,8 @@ static int dpaa2_switch_port_stop(struct net_device *netdev)
                netif_carrier_off(netdev);
        }
 
+       mutex_unlock(&port_priv->mac_lock);
+
        err = dpsw_if_disable(port_priv->ethsw_data->mc_io, 0,
                              port_priv->ethsw_data->dpsw_handle,
                              port_priv->idx);
@@ -1460,7 +1472,9 @@ static int dpaa2_switch_port_connect_mac(struct ethsw_port_priv *port_priv)
                }
        }
 
+       mutex_lock(&port_priv->mac_lock);
        port_priv->mac = mac;
+       mutex_unlock(&port_priv->mac_lock);
 
        return 0;
 
@@ -1473,9 +1487,12 @@ err_free_mac:
 
 static void dpaa2_switch_port_disconnect_mac(struct ethsw_port_priv *port_priv)
 {
-       struct dpaa2_mac *mac = port_priv->mac;
+       struct dpaa2_mac *mac;
 
+       mutex_lock(&port_priv->mac_lock);
+       mac = port_priv->mac;
        port_priv->mac = NULL;
+       mutex_unlock(&port_priv->mac_lock);
 
        if (!mac)
                return;
@@ -1494,6 +1511,7 @@ static irqreturn_t dpaa2_switch_irq0_handler_thread(int irq_num, void *arg)
        struct ethsw_port_priv *port_priv;
        u32 status = ~0;
        int err, if_id;
+       bool had_mac;
 
        err = dpsw_get_irq_status(ethsw->mc_io, 0, ethsw->dpsw_handle,
                                  DPSW_IRQ_INDEX_IF, &status);
@@ -1512,7 +1530,12 @@ static irqreturn_t dpaa2_switch_irq0_handler_thread(int irq_num, void *arg)
 
        if (status & DPSW_IRQ_EVENT_ENDPOINT_CHANGED) {
                rtnl_lock();
-               if (dpaa2_switch_port_has_mac(port_priv))
+               /* We can avoid locking because the "endpoint changed" IRQ
+                * handler is the only one who changes priv->mac at runtime,
+                * so we are not racing with anyone.
+                */
+               had_mac = !!port_priv->mac;
+               if (had_mac)
                        dpaa2_switch_port_disconnect_mac(port_priv);
                else
                        dpaa2_switch_port_connect_mac(port_priv);
@@ -3255,6 +3278,8 @@ static int dpaa2_switch_probe_port(struct ethsw_core *ethsw,
        port_priv->netdev = port_netdev;
        port_priv->ethsw_data = ethsw;
 
+       mutex_init(&port_priv->mac_lock);
+
        port_priv->idx = port_idx;
        port_priv->stp_state = BR_STATE_FORWARDING;
 

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.h b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.h
index 9898073abe012a9ff5fba1ecfee4fd17e320950b..42b3ca73f55d54e78abeead23cf89946de579770 100644 (file)
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.h
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.h
@@ -161,6 +161,8 @@ struct ethsw_port_priv {
 
        struct dpaa2_switch_filter_block *filter_block;
        struct dpaa2_mac        *mac;
+       /* Protects against changes to port_priv->mac */
+       struct mutex            mac_lock;
 };
 
 /* Switch data */