[PATCH net-next v3 2/2] ixgbe: use mii_bus to handle MII related ioctls

[Steve Douthit]

Use the mii_bus callbacks to address the entire clause 22/45 address
space.  Enables userspace to poke switch registers instead of a single
PHY address.

The ixgbe firmware may be polling PHYs in a way that is not protected by
the mii_bus lock.  This isn't new behavior, but as Andrew Lunn pointed
out there are more addresses available for conflicts.

Signed-off-by: Stephen Douthit <steph...@silicom-usa.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c 
b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 82af3b24d222..fb066c491abe 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -8790,6 +8790,15 @@ ixgbe_mdio_read(struct net_device *netdev, int prtad, 
int devad, u16 addr)
        u16 value;
        int rc;
 
+       if (adapter->mii_bus) {
+               int regnum = addr;
+
+               if (devad != MDIO_DEVAD_NONE)
+                       regnum |= (devad << 16) | MII_ADDR_C45;
+
+               return mdiobus_read(adapter->mii_bus, prtad, regnum);
+       }
+
        if (prtad != hw->phy.mdio.prtad)
                return -EINVAL;
        rc = hw->phy.ops.read_reg(hw, addr, devad, &value);
@@ -8804,6 +8813,15 @@ static int ixgbe_mdio_write(struct net_device *netdev, 
int prtad, int devad,
        struct ixgbe_adapter *adapter = netdev_priv(netdev);
        struct ixgbe_hw *hw = &adapter->hw;
 
+       if (adapter->mii_bus) {
+               int regnum = addr;
+
+               if (devad != MDIO_DEVAD_NONE)
+                       regnum |= (devad << 16) | MII_ADDR_C45;
+
+               return mdiobus_write(adapter->mii_bus, prtad, regnum, value);
+       }
+
        if (prtad != hw->phy.mdio.prtad)
                return -EINVAL;
        return hw->phy.ops.write_reg(hw, addr, devad, value);
-- 
2.17.2