net: mdio: introduce a shutdown method to mdio device drivers

MDIO-attached devices might have interrupts and other things that might
need quiesced when we kexec into a new kernel. Things are even more
creepy when those interrupt lines are shared, and in that case it is
absolutely mandatory to disable all interrupt sources.

Moreover, MDIO devices might be DSA switches, and DSA needs its own
shutdown method to unlink from the DSA master, which is a new
requirement that appeared after commit 6a3226035fc2 ("net: dsa: link
interfaces with the DSA master to get rid of lockdep warnings").

So introduce a ->shutdown method in the MDIO device driver structure.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/mdio_device.c b/drivers/net/phy/mdio_device.c
index c94cb5382dc922e5cec73e053f863e8b28742974..250742ffdfd91961301020c5ea721fccb33093b9 100644 (file)
--- a/drivers/net/phy/mdio_device.c
+++ b/drivers/net/phy/mdio_device.c
@@ -179,6 +179,16 @@ static int mdio_remove(struct device *dev)
        return 0;
 }
 
+static void mdio_shutdown(struct device *dev)
+{
+       struct mdio_device *mdiodev = to_mdio_device(dev);
+       struct device_driver *drv = mdiodev->dev.driver;
+       struct mdio_driver *mdiodrv = to_mdio_driver(drv);
+
+       if (mdiodrv->shutdown)
+               mdiodrv->shutdown(mdiodev);
+}
+
 /**
  * mdio_driver_register - register an mdio_driver with the MDIO layer
  * @drv: new mdio_driver to register
@@ -193,6 +203,7 @@ int mdio_driver_register(struct mdio_driver *drv)
        mdiodrv->driver.bus = &mdio_bus_type;
        mdiodrv->driver.probe = mdio_probe;
        mdiodrv->driver.remove = mdio_remove;
+       mdiodrv->driver.shutdown = mdio_shutdown;
 
        retval = driver_register(&mdiodrv->driver);
        if (retval) {

diff --git a/include/linux/mdio.h b/include/linux/mdio.h
index ffb787d5ebde3045dea36bcce8b37953dae43b6e..5e6dc38f418e48c3b2ce3f3d08a10ae6bbb3e675 100644 (file)
--- a/include/linux/mdio.h
+++ b/include/linux/mdio.h
@@ -80,6 +80,9 @@ struct mdio_driver {
 
        /* Clears up any memory if needed */
        void (*remove)(struct mdio_device *mdiodev);
+
+       /* Quiesces the device on system shutdown, turns off interrupts etc */
+       void (*shutdown)(struct mdio_device *mdiodev);
 };
 
 static inline struct mdio_driver *