Add a mechanism for mlx4 protocol drivers to get a pointer to other
drivers's device objects.  For this, an exported function,
mlx4_get_protocol_dev() is added, which allows a driver to get some
other driver's device based on the protocol that the driver
implements.  Two protocols are added: MLX4_PROTOCOL_IB and
MLX4_PROTOCOL_EN.

This will be used in mlx4 IBoE support so that mlx4_ib can find the
corresponding mlx4_en netdev.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>

[ Clean up and rename a few things.  - Roland ]

Signed-off-by: Roland Dreier <rolandd@cisco.com>

The struct mlx4_interface.event() method was supposed to get an enum
mlx4_dev_event, but the driver code was actually passing in the
hardware enum mlx4_event values.  Fix up the callers of
mlx4_dispatch_event() so that they pass in the right type of value,
and fix up the event method in mlx4_ib so that it can handle the enum
mlx4_dev_event values.

This eliminates the need for the subtype parameter to the event
method, so remove it.

This also fixes the sparse warning

    drivers/net/mlx4/intf.c:127:48: warning: mixing different enum types
    drivers/net/mlx4/intf.c:127:48:     int enum mlx4_event  versus
    drivers/net/mlx4/intf.c:127:48:     int enum mlx4_dev_event

Signed-off-by: Roland Dreier <rolandd@cisco.com>

Add an InfiniBand driver for Mellanox ConnectX adapters.  Because
these adapters can also be used as ethernet NICs and Fibre Channel 
HBAs, the driver is split into two modules: 
 
  mlx4_core: Handles low-level things like device initialization and 
    processing firmware commands.  Also controls resource allocation 
    so that the InfiniBand, ethernet and FC functions can share a 
    device without stepping on each other. 
 
  mlx4_ib: Handles InfiniBand-specific things; plugs into the 
    InfiniBand midlayer. 

Signed-off-by: Roland Dreier <rolandd@cisco.com>