diff options
author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2022-11-29 16:12:19 +0200 |
---|---|---|
committer | Paolo Abeni <pabeni@redhat.com> | 2022-12-01 13:40:22 +0100 |
commit | 2291982e29b1aa6e628d3072ef533aeb6299945f (patch) | |
tree | e82e3a2e3671eed8b54899578945034eaaa80a5a /drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h | |
parent | 55f90a4d07ec32279c622a25be4e2555ee9d7dff (diff) |
net: dpaa2-eth: serialize changes to priv->mac with a mutex
The dpaa2 architecture permits dynamic connections between objects on
the fsl-mc bus, specifically between a DPNI object (represented by a
struct net_device) and a DPMAC object (represented by a struct phylink).
The DPNI driver is notified when those connections are created/broken
through the dpni_irq0_handler_thread() method. To ensure that ethtool
operations, as well as netdev up/down operations serialize with the
connection/disconnection of the DPNI with a DPMAC,
dpni_irq0_handler_thread() takes the rtnl_lock() to block those other
operations from taking place.
There is code called by dpaa2_mac_connect() which wants to acquire the
rtnl_mutex once again, see phylink_create() -> phylink_register_sfp() ->
sfp_bus_add_upstream() -> rtnl_lock(). So the strategy doesn't quite
work out, even though it's fairly simple.
Create a different strategy, where all code paths in the dpaa2-eth
driver access priv->mac only while they are holding priv->mac_lock.
The phylink instance is not created or connected to the PHY under the
priv->mac_lock, but only assigned to priv->mac then. This will eliminate
the reliance on the rtnl_mutex.
Add lockdep annotations and put comments where holding the lock is not
necessary, and priv->mac can be dereferenced freely.
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>
Diffstat (limited to 'drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h')
-rw-r--r-- | drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h index 04270ae44d84..d56d7a13262e 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h @@ -615,6 +615,8 @@ struct dpaa2_eth_priv { #endif struct dpaa2_mac *mac; + /* Serializes changes to priv->mac */ + struct mutex mac_lock; struct workqueue_struct *dpaa2_ptp_wq; struct work_struct tx_onestep_tstamp; struct sk_buff_head tx_skbs; @@ -768,11 +770,15 @@ static inline unsigned int dpaa2_eth_rx_head_room(struct dpaa2_eth_priv *priv) static inline bool dpaa2_eth_is_type_phy(struct dpaa2_eth_priv *priv) { + lockdep_assert_held(&priv->mac_lock); + return dpaa2_mac_is_type_phy(priv->mac); } static inline bool dpaa2_eth_has_mac(struct dpaa2_eth_priv *priv) { + lockdep_assert_held(&priv->mac_lock); + return priv->mac ? true : false; } |