drm/radeon: Make vramlimit parameter actually work.

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_device.c

@@ -301,6 +301,8 @@ void radeon_vram_location(struct radeon_device *rdev, struct radeon_mc *mc, u64
 		mc->mc_vram_size = mc->aper_size;
 	}
 	mc->vram_end = mc->vram_start + mc->mc_vram_size - 1;
+	if (radeon_vram_limit && radeon_vram_limit < mc->real_vram_size)
+		mc->real_vram_size = radeon_vram_limit;
 	dev_info(rdev->dev, "VRAM: %lluM 0x%016llX - 0x%016llX (%lluM used)\n",
 			mc->mc_vram_size >> 20, mc->vram_start,
 			mc->vram_end, mc->real_vram_size >> 20);