3840a656f6
AGP mappings are not cache coherent, so userptr support won't work. Additional to that the AGP implementation uses a different ttm_tt container structure so we run into problems if we cast the pointer without checking if it's the right type. Signed-off-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>