From: Guennadi Liakhovetski <g.liakhovetski@gmx.de>

Removes the page_to_virt and maps sg lists dynamically.
This makes the driver work with highmem pages.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Jamie Lenehan <lenehan@twibble.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>