libxl: arm: Split make_virtio_mmio_node()

make_virtio_mmio_node() creates the DT node for simple MMIO devices
currently, i.e. the ones that don't require any additional properties.

In order to allow using it for other complex device types, split the
functionality into two, one where the fdt node isn't closed and the
other one to create a simple DT node.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>

tools/libs/light/libxl_arm.c

@@ -907,9 +907,9 @@ static int make_xen_iommu_node(libxl__gc *gc, void *fdt)
     return 0;
 }
 
-static int make_virtio_mmio_node(libxl__gc *gc, void *fdt,
-                                 uint64_t base, uint32_t irq,
-                                 uint32_t backend_domid)
+/* The caller is responsible to complete / close the fdt node */
+static int make_virtio_mmio_node_common(libxl__gc *gc, void *fdt, uint64_t base,
+                                        uint32_t irq, uint32_t backend_domid)
 {
     int res;
     gic_interrupt intr;
@@ -942,10 +942,18 @@ static int make_virtio_mmio_node(libxl__gc *gc, void *fdt,
         if (res) return res;
     }
 
-    res = fdt_end_node(fdt);
+    return res;
+}
+
+static int make_virtio_mmio_node(libxl__gc *gc, void *fdt, uint64_t base,
+                                 uint32_t irq, uint32_t backend_domid)
+{
+    int res;
+
+    res = make_virtio_mmio_node_common(gc, fdt, base, irq, backend_domid);
     if (res) return res;
 
-    return 0;
+    return fdt_end_node(fdt);
 }
 
 static const struct arch_info *get_arch_info(libxl__gc *gc,