Taken from https://build.opensuse.org/package/view_file/X11:Drivers:Video/nvidia-gfxG04/kernel-5.12.patch
Credit to Larry Finger <Larry.Finger@lwfinger.net>

Index: NVIDIA-Linux-x86_64-390.141-no-compat32/kernel/nvidia-drm/nvidia-drm-drv.c
===================================================================
--- NVIDIA-Linux-x86_64-390.141-no-compat32.orig/kernel/nvidia-drm/nvidia-drm-drv.c
+++ NVIDIA-Linux-x86_64-390.141-no-compat32/kernel/nvidia-drm/nvidia-drm-drv.c
@@ -741,6 +741,17 @@ static struct drm_driver nv_drm_driver =
 #endif
 };
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
+/* Starting with kernel 5.12, drm_gem_dumb_destroy() is no longer exported.
+ * For that reason, we need to supply a replacement version.
+ */
+int replace_dumb_destroy(struct drm_file *file,
+			 struct drm_device *dev,
+			 u32 handle)
+{
+	return drm_gem_handle_delete(file, handle);
+}
+#endif
 
 /*
  * Update the global nv_drm_driver for the intended features.
@@ -764,7 +775,11 @@ static void nv_drm_update_drm_driver_fea
 
     nv_drm_driver.dumb_create      = nv_drm_dumb_create;
     nv_drm_driver.dumb_map_offset  = nv_drm_dumb_map_offset;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 12, 0)
     nv_drm_driver.dumb_destroy     = drm_gem_dumb_destroy;
+#else
+    nv_drm_driver.dumb_destroy     = replace_dumb_destroy;
+#endif
 #endif /* NV_DRM_ATOMIC_MODESET_AVAILABLE */
 }