[PATCH 5.15 068/570] net: dpaa2-switch: serialize changes to priv->mac with a mutex

Greg Kroah-Hartman
2026-04-13T16:20:59Z

From: Vladimir Oltean <vladimir.oltean@nxp.com>

[ Upstream commit 3c7f44fa9c4c8a9154935ca49e4cf45c14240335 ]

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>
Stable-dep-of: 74badb9c20b1 ("dpaa2-switch: Fix interrupt storm after receiving bad if_id in IRQ handler")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../freescale/dpaa2/dpaa2-switch-ethtool.c | 32 +++++++++++++++----
.../ethernet/freescale/dpaa2/dpaa2-switch.c | 31 ++++++++++++++++--
.../ethernet/freescale/dpaa2/dpaa2-switch.h | 2 ++
3 files changed, 55 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch-ethtool.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch-ethtool.c
index 0b41a945e0fff..dc9f4ad8a061d 100644
--- 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);
@@ -196,8 +210,12 @@ 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 a2812229511c3..92500e55ab931 100644
--- 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))
phylink_start(port_priv->mac->phylink);

+ 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)) {
phylink_stop(port_priv->mac->phylink);
} 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);
@@ -1467,7 +1479,9 @@ 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;

@@ -1482,9 +1496,12 @@ static int dpaa2_switch_port_connect_mac(struct ethsw_port_priv *port_priv)

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;
@@ -1503,6 +1520,7 @@ 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);
@@ -1525,7 +1543,12 @@ 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);
@@ -3281,6 +3304,8 @@ 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 9898073abe012..42b3ca73f55d5 100644
--- 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 */
--
2.51.0