radeonsi: Export signalled sync file instead of -1.

-1 is considered an error for EGL_ANDROID_native_fence_sync, so
we need to actually create a sync file.

Fixes: f536f45250 "radeonsi: implement sync_file import/export"
Reviewed-by: Dave Airlie <airlied@redhat.com>

src/gallium/drivers/radeon/radeon_winsys.h

@@ -610,6 +610,11 @@ struct radeon_winsys {
     int (*fence_export_sync_file)(struct radeon_winsys *ws,
 				  struct pipe_fence_handle *fence);
 
+    /**
+     * Return a sync file FD that is already signalled.
+     */
+    int (*export_signalled_sync_file)(struct radeon_winsys *ws);
+
     /**
      * Initialize surface
      *

src/gallium/drivers/radeonsi/si_fence.c

@@ -356,6 +356,8 @@ static int si_fence_get_fd(struct pipe_screen *screen,
 
 	/* If we don't have FDs at this point, it means we don't have fences
 	 * either. */
+	if (sdma_fd == -1 && gfx_fd == -1)
+		return ws->export_signalled_sync_file(ws);
 	if (sdma_fd == -1)
 		return gfx_fd;
 	if (gfx_fd == -1)

src/gallium/winsys/amdgpu/drm/amdgpu_cs.c

@@ -114,6 +114,27 @@ static int amdgpu_fence_export_sync_file(struct radeon_winsys *rws,
    return fd;
 }
 
+static int amdgpu_export_signalled_sync_file(struct radeon_winsys *rws)
+{
+   struct amdgpu_winsys *ws = amdgpu_winsys(rws);
+   uint32_t syncobj;
+   int fd = -1;
+
+   int r = amdgpu_cs_create_syncobj2(ws->dev, DRM_SYNCOBJ_CREATE_SIGNALED,
+                                     &syncobj);
+   if (r) {
+      return -1;
+   }
+
+   r = amdgpu_cs_syncobj_export_sync_file(ws->dev, syncobj, &fd);
+   if (r) {
+      fd = -1;
+   }
+
+   amdgpu_cs_destroy_syncobj(ws->dev, syncobj);
+   return fd;
+}
+
 static void amdgpu_fence_submitted(struct pipe_fence_handle *fence,
                                    uint64_t seq_no,
                                    uint64_t *user_fence_cpu_address)
@@ -1560,4 +1581,5 @@ void amdgpu_cs_init_functions(struct amdgpu_winsys *ws)
    ws->base.fence_reference = amdgpu_fence_reference;
    ws->base.fence_import_sync_file = amdgpu_fence_import_sync_file;
    ws->base.fence_export_sync_file = amdgpu_fence_export_sync_file;
+   ws->base.export_signalled_sync_file = amdgpu_export_signalled_sync_file;
 }