x86, gart: Make sure GART does not map physmem above 1TB

x86, gart: Make sure GART does not map physmem above 1TB

BugLink: http://bugs.launchpad.net/bugs/775809

commit 665d3e2af83c8fbd149534db8f57d82fa6fa6753 upstream.

The GART can only map physical memory below 1TB. Make sure
the gart driver in the kernel does not try to map memory
above 1TB.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Link: http://lkml.kernel.org/r/1303134346-5805-5-git-send-email-joerg.roedel@amd.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>