At 1000Mbps link speed, one of the MAC's internal clocks can be stopped for
up to 4us when entering K1 (a power mode of the MAC-PHY interconnect).  If
the MAC is waiting for completion indications for 2 DMA write requests into
Host memory (e.g. descriptor writeback or Rx packet writing) and the
indications occur while the clock is stopped, both indications will be
missed by the MAC causing the MAC to wait for the completion indications
and be unable to generate further DMA write requests.  This results in an
apparent hardware hang.

Work-around the issue by disabling the de-assertion of the clock request
when 1000Mbps link is acquired (K1 must be disabled while doing this).
Signed-off-by: NBruce Allan <bruce.w.allan@intel.com>
Tested-by: NJeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Move #defines and function prototypes specific to the ICH/PCH family of
devices (ICH8/82562, ICH8/82566, ICH8/82567, ICH9/82562, ICH9/82566,
ICH9/82567, ICH10/82567, 82577, 82578, 82579, I217, I218) to the new
ich8lan.h header file (the convention for Intel wired ethernet drivers is
to use the name of the first device in the family for related file and
function names).  These defines and function prototypes can be used by
other files in the driver and moving them to the ICH/PCH-family-specific
file makes it clearer to which devices they are applicable.
Signed-off-by: NBruce Allan <bruce.w.allan@intel.com>
Tested-by: NAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>