drm/fence: add drm_crtc_create_fence()

Instead of dealing with crtc details inside drm_atomic.c we should
just export a function that creates a new crtc fence for us and
use that.

Suggested-by: Chris Wilson <[e-mail]>
Signed-off-by: Gustavo Padovan <[e-mail]>
Reviewed-by: Daniel Vetter <[e-mail]>
Link: http://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/drm_atomic.c

···
  *	helpers and for the DRM event handling for existing userspace.
  */
 
-static struct dma_fence *get_crtc_fence(struct drm_crtc *crtc)
-{
-	struct dma_fence *fence;
-
-	fence = kzalloc(sizeof(*fence), GFP_KERNEL);
-	if (!fence)
-		return NULL;
-
-	dma_fence_init(fence, &drm_crtc_fence_ops, &crtc->fence_lock,
-		       crtc->fence_context, ++crtc->fence_seqno);
-
-	return fence;
-}
-
 struct drm_out_fence_state {
 	s64 __user *out_fence_ptr;
 	struct sync_file *sync_file;
···
 			f[*num_fences].out_fence_ptr = fence_ptr;
 			*fence_state = f;
 
-			fence = get_crtc_fence(crtc);
+			fence = drm_crtc_create_fence(crtc);
 			if (!fence)
 				return -ENOMEM;
 

drivers/gpu/drm/drm_crtc.c

···
 #endif
 }
 
+static const struct dma_fence_ops drm_crtc_fence_ops;
+
 static struct drm_crtc *fence_to_crtc(struct dma_fence *fence)
 {
 	BUG_ON(fence->ops != &drm_crtc_fence_ops);
···
 	return true;
 }
 
-const struct dma_fence_ops drm_crtc_fence_ops = {
+static const struct dma_fence_ops drm_crtc_fence_ops = {
 	.get_driver_name = drm_crtc_fence_get_driver_name,
 	.get_timeline_name = drm_crtc_fence_get_timeline_name,
 	.enable_signaling = drm_crtc_fence_enable_signaling,
 	.wait = dma_fence_default_wait,
 };
+
+struct dma_fence *drm_crtc_create_fence(struct drm_crtc *crtc)
+{
+	struct dma_fence *fence;
+
+	fence = kzalloc(sizeof(*fence), GFP_KERNEL);
+	if (!fence)
+		return NULL;
+
+	dma_fence_init(fence, &drm_crtc_fence_ops, &crtc->fence_lock,
+		       crtc->fence_context, ++crtc->fence_seqno);
+
+	return fence;
+}
 
 /**
  * drm_crtc_init_with_planes - Initialise a new CRTC object with

drivers/gpu/drm/drm_crtc_internal.h

···
 int drm_crtc_register_all(struct drm_device *dev);
 void drm_crtc_unregister_all(struct drm_device *dev);
 
-extern const struct dma_fence_ops drm_crtc_fence_ops;
+struct dma_fence *drm_crtc_create_fence(struct drm_crtc *crtc);
 
 /* IOCTLs */
 int drm_mode_getcrtc(struct drm_device *dev,