When allocating more than 2GB of GART the array of pages
gets to big for kzalloc, use vzalloc instead.
Signed-off-by: NChristian König <deathsimple@vodafone.de>
Reviewed-by: NMichel Dänzer <michel.daenzer@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>