HDP_NONSURFACE_BASE
WREG32(HDP_NONSURFACE_BASE, (rdev->mc.vram_start >> 8));
WREG32(HDP_NONSURFACE_BASE, (rdev->mc.vram_start >> 8));
WREG32(HDP_NONSURFACE_BASE, (rdev->mc.vram_start >> 8));
WREG32(HDP_NONSURFACE_BASE, (rdev->mc.vram_start >> 8));
WREG32(HDP_NONSURFACE_BASE, (rdev->mc.vram_start >> 8));