drm/vmwgfx: convert to idr_alloc()

Convert to the much saner new idr interface.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NDavid Airlie <airlied@linux.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/gpu/drm/vmwgfx/vmwgfx_resource.c

@@ -177,17 +177,16 @@ int vmw_resource_alloc_id(struct vmw_resource *res)
 
 	BUG_ON(res->id != -1);
 
-	do {
-		if (unlikely(idr_pre_get(idr, GFP_KERNEL) == 0))
-			return -ENOMEM;
-
-		write_lock(&dev_priv->resource_lock);
-		ret = idr_get_new_above(idr, res, 1, &res->id);
-		write_unlock(&dev_priv->resource_lock);
+	idr_preload(GFP_KERNEL);
+	write_lock(&dev_priv->resource_lock);
 
-	} while (ret == -EAGAIN);
+	ret = idr_alloc(idr, res, 1, 0, GFP_NOWAIT);
+	if (ret >= 0)
+		res->id = ret;
 
-	return ret;
+	write_unlock(&dev_priv->resource_lock);
+	idr_preload_end();
+	return ret < 0 ? ret : 0;
 }
 
 /**