target/linux/brcm2708/patches-4.14/950-0292-net-mdiobus-add-unlocked-accessors.patch

   1 From b2b8b06f18281c637da274b18e330bc52351637e Mon Sep 17 00:00:00 2001
   2 From: Russell King <rmk+kernel@armlinux.org.uk>
   3 Date: Tue, 2 Jan 2018 10:58:27 +0000
   4 Subject: [PATCH 292/454] net: mdiobus: add unlocked accessors
   5
   6 commit 34dc08e4be208539b7c4aa8154a610e1736705e8 upstream.
   7
   8 Add unlocked versions of the bus accessors, which allows access to the
   9 bus with all the tracing. These accessors validate that the bus mutex
  10 is held, which is a basic requirement for all mii bus accesses.
  11
  12 Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
  13 Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
  14 Signed-off-by: David S. Miller <davem@davemloft.net>
  15 ---
  16  drivers/net/phy/mdio_bus.c | 65 +++++++++++++++++++++++++++++++-------
  17  include/linux/mdio.h       |  3 ++
  18  2 files changed, 56 insertions(+), 12 deletions(-)
  19
  20 --- a/drivers/net/phy/mdio_bus.c
  21 +++ b/drivers/net/phy/mdio_bus.c
  22 @@ -494,6 +494,55 @@ struct phy_device *mdiobus_scan(struct m
  23  EXPORT_SYMBOL(mdiobus_scan);
  24
  25  /**
  26 + * __mdiobus_read - Unlocked version of the mdiobus_read function
  27 + * @bus: the mii_bus struct
  28 + * @addr: the phy address
  29 + * @regnum: register number to read
  30 + *
  31 + * Read a MDIO bus register. Caller must hold the mdio bus lock.
  32 + *
  33 + * NOTE: MUST NOT be called from interrupt context.
  34 + */
  35 +int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
  36 +{
  37 +       int retval;
  38 +
  39 +       WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
  40 +
  41 +       retval = bus->read(bus, addr, regnum);
  42 +
  43 +       trace_mdio_access(bus, 1, addr, regnum, retval, retval);
  44 +
  45 +       return retval;
  46 +}
  47 +EXPORT_SYMBOL(__mdiobus_read);
  48 +
  49 +/**
  50 + * __mdiobus_write - Unlocked version of the mdiobus_write function
  51 + * @bus: the mii_bus struct
  52 + * @addr: the phy address
  53 + * @regnum: register number to write
  54 + * @val: value to write to @regnum
  55 + *
  56 + * Write a MDIO bus register. Caller must hold the mdio bus lock.
  57 + *
  58 + * NOTE: MUST NOT be called from interrupt context.
  59 + */
  60 +int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
  61 +{
  62 +       int err;
  63 +
  64 +       WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
  65 +
  66 +       err = bus->write(bus, addr, regnum, val);
  67 +
  68 +       trace_mdio_access(bus, 0, addr, regnum, val, err);
  69 +
  70 +       return err;
  71 +}
  72 +EXPORT_SYMBOL(__mdiobus_write);
  73 +
  74 +/**
  75   * mdiobus_read_nested - Nested version of the mdiobus_read function
  76   * @bus: the mii_bus struct
  77   * @addr: the phy address
  78 @@ -513,11 +562,9 @@ int mdiobus_read_nested(struct mii_bus *
  79         BUG_ON(in_interrupt());
  80
  81         mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
  82 -       retval = bus->read(bus, addr, regnum);
  83 +       retval = __mdiobus_read(bus, addr, regnum);
  84         mutex_unlock(&bus->mdio_lock);
  85
  86 -       trace_mdio_access(bus, 1, addr, regnum, retval, retval);
  87 -
  88         return retval;
  89  }
  90  EXPORT_SYMBOL(mdiobus_read_nested);
  91 @@ -539,11 +586,9 @@ int mdiobus_read(struct mii_bus *bus, in
  92         BUG_ON(in_interrupt());
  93
  94         mutex_lock(&bus->mdio_lock);
  95 -       retval = bus->read(bus, addr, regnum);
  96 +       retval = __mdiobus_read(bus, addr, regnum);
  97         mutex_unlock(&bus->mdio_lock);
  98
  99 -       trace_mdio_access(bus, 1, addr, regnum, retval, retval);
 100 -
 101         return retval;
 102  }
 103  EXPORT_SYMBOL(mdiobus_read);
 104 @@ -569,11 +614,9 @@ int mdiobus_write_nested(struct mii_bus
 105         BUG_ON(in_interrupt());
 106
 107         mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
 108 -       err = bus->write(bus, addr, regnum, val);
 109 +       err = __mdiobus_write(bus, addr, regnum, val);
 110         mutex_unlock(&bus->mdio_lock);
 111
 112 -       trace_mdio_access(bus, 0, addr, regnum, val, err);
 113 -
 114         return err;
 115  }
 116  EXPORT_SYMBOL(mdiobus_write_nested);
 117 @@ -596,11 +639,9 @@ int mdiobus_write(struct mii_bus *bus, i
 118         BUG_ON(in_interrupt());
 119
 120         mutex_lock(&bus->mdio_lock);
 121 -       err = bus->write(bus, addr, regnum, val);
 122 +       err = __mdiobus_write(bus, addr, regnum, val);
 123         mutex_unlock(&bus->mdio_lock);
 124
 125 -       trace_mdio_access(bus, 0, addr, regnum, val, err);
 126 -
 127         return err;
 128  }
 129  EXPORT_SYMBOL(mdiobus_write);
 130 --- a/include/linux/mdio.h
 131 +++ b/include/linux/mdio.h
 132 @@ -257,6 +257,9 @@ static inline u16 ethtool_adv_to_mmd_eee
 133         return reg;
 134  }
 135
 136 +int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum);
 137 +int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val);
 138 +
 139  int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum);
 140  int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum);
 141  int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val);