Not sure which is the name of your video card, but I think in general all the page flip API should have access to the scan buffer (see link above). For Intel these are possible APIs
static void do_intel_finish_page_flip(struct drm_device *dev,
void intel_finish_page_flip(struct drm_device *dev, int pipe)
do_intel_finish_page_flip(dev, crtc);
void intel_finish_page_flip_plane(struct drm_device *dev, int plane)
do_intel_finish_page_flip(dev, crtc);
void intel_prepare_page_flip(struct drm_device *dev, int plane)
* is also accompanied by a spurious intel_prepare_page_flip().
inline static void intel_mark_page_flip_active(struct intel_crtc *intel_crtc)