int i915_gem_init_ringbuffer(struct drm_device *dev);
void i915_gem_cleanup_ringbuffer(struct drm_device *dev);
int i915_gem_do_init(struct drm_device *dev, unsigned long start,
int i915_gem_init_ringbuffer(struct drm_device *dev);
void i915_gem_cleanup_ringbuffer(struct drm_device *dev);
int i915_gem_do_init(struct drm_device *dev, unsigned long start,