AMDGPU_GFXHUB_START
(vmhub - AMDGPU_GFXHUB_START) << AMDGPU_VMHUB_IDX_SHIFT;
#define AMDGPU_GFXHUB(x) (AMDGPU_GFXHUB_START + (x))
#define AMDGPU_IS_GFXHUB(x) ((x) >= AMDGPU_GFXHUB_START && (x) < AMDGPU_MMHUB0_START)