staging/android/sync: add sync_fence_create_dma

This allows users of dma fences to create a android fence.

v2: Added kerneldoc. (Tvrtko Ursulin).

v4: Updated comments from review feedback my Maarten.

Signed-off-by: Maarten Lankhorst <[e-mail]>
Signed-off-by: Tvrtko Ursulin <[e-mail]>
Cc: Maarten Lankhorst <[e-mail]>
Cc: Daniel Vetter <[e-mail]>
Cc: [e-mail]
Cc: Riley Andrews <[e-mail]>
Cc: Arve Hjønnevåg <[e-mail]>
Reviewed-by: Jesse Barnes <[e-mail]>
Tested-by: Jesse Barnes <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/android/sync.c

···
 }
 
 /* TODO: implement a create which takes more that one sync_pt */
-struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt)
+struct sync_fence *sync_fence_create_dma(const char *name, struct fence *pt)
 {
 	struct sync_fence *fence;
 
···
 	fence->num_fences = 1;
 	atomic_set(&fence->status, 1);
 
-	fence->cbs[0].sync_pt = &pt->base;
+	fence->cbs[0].sync_pt = pt;
 	fence->cbs[0].fence = fence;
-	if (fence_add_callback(&pt->base, &fence->cbs[0].cb,
-			       fence_check_cb_func))
+	if (fence_add_callback(pt, &fence->cbs[0].cb, fence_check_cb_func))
 		atomic_dec(&fence->status);
 
 	sync_fence_debug_add(fence);
 
 	return fence;
+}
+EXPORT_SYMBOL(sync_fence_create_dma);
+
+struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt)
+{
+	return sync_fence_create_dma(name, &pt->base);
 }
 EXPORT_SYMBOL(sync_fence_create);
 

drivers/staging/android/sync.h

···
  */
 struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt);
 
+/**
+ * sync_fence_create_dma() - creates a sync fence from dma-fence
+ * @name:	name of fence to create
+ * @pt:	dma-fence to add to the fence
+ *
+ * Creates a fence containg @pt.  Once this is called, the fence takes
+ * ownership of @pt.
+ */
+struct sync_fence *sync_fence_create_dma(const char *name, struct fence *pt);
+
 /*
  * API for sync_fence consumers
  */