of: Always unflatten in unflatten_and_copy_device_tree()

We want to populate an empty DT whenever CONFIG_OF is enabled so that
overlays can be applied and the DT unit tests can be run. Make
unflatten_and_copy_device_tree() stop printing a warning if the
'initial_boot_params' pointer is NULL. Instead, simply copy the dtb if
there is one and then unflatten it. If there isn't a DT to copy, then
the call to unflatten_device_tree() is largely a no-op, so nothing
really changes here.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240217010557.2381548-2-sboyd@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index bf502ba8da9586112a5a63dd7e787fc3985dcf94..dfeba8b8ce9453f335ad6c882efd814cbfcf18af 100644 (file)
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -1318,6 +1318,21 @@ bool __init early_init_dt_scan(void *params)
        return true;
 }
 
+static void *__init copy_device_tree(void *fdt)
+{
+       int size;
+       void *dt;
+
+       size = fdt_totalsize(fdt);
+       dt = early_init_dt_alloc_memory_arch(size,
+                                            roundup_pow_of_two(FDT_V17_SIZE));
+
+       if (dt)
+               memcpy(dt, fdt, size);
+
+       return dt;
+}
+
 /**
  * unflatten_device_tree - create tree of device_nodes from flat blob
  *
@@ -1350,22 +1365,9 @@ void __init unflatten_device_tree(void)
  */
 void __init unflatten_and_copy_device_tree(void)
 {
-       int size;
-       void *dt;
-
-       if (!initial_boot_params) {
-               pr_warn("No valid device tree found, continuing without\n");
-               return;
-       }
+       if (initial_boot_params)
+               initial_boot_params = copy_device_tree(initial_boot_params);
 
-       size = fdt_totalsize(initial_boot_params);
-       dt = early_init_dt_alloc_memory_arch(size,
-                                            roundup_pow_of_two(FDT_V17_SIZE));
-
-       if (dt) {
-               memcpy(dt, initial_boot_params, size);
-               initial_boot_params = dt;
-       }
        unflatten_device_tree();
 }