e1000e: enable ECC on I217/I218 to catch packet buffer memory errors

e1000e: enable ECC on I217/I218 to catch packet buffer memory errors

commit 286003048aaef49b26bb9d93611dc69085e8982e upstream.

In rare instances, memory errors have been detected in the internal packet
buffer memory on I217/I218 when stressed under certain environmental
conditions.  Enable Error Correcting Code (ECC) in hardware to catch both
correctable and uncorrectable errors.  Correctable errors will be handled
by the hardware.  Uncorrectable errors in the packet buffer will cause the
packet to be received with an error indication in the buffer descriptor
causing the packet to be discarded.  If the uncorrectable error is in the
descriptor itself, the hardware will stop and interrupt the driver
indicating the error.  The driver will then reset the hardware in order to
clear the error and restart.

Both types of errors will be accounted for in statistics counters.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>