Quoting David Gow (2024-01-15 21:03:12)
> On Sat, 13 Jan 2024 at 04:07, Stephen Boyd <sboyd@xxxxxxxxxx> wrote:
> >
> > Add a KUnit test that confirms a DTB has been loaded, i.e. there is a
> > root node, and that the of_have_populated_dt() API works properly.
> >
> > Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> > Cc: Frank Rowand <frowand.list@xxxxxxxxx>
> > Cc: David Gow <davidgow@xxxxxxxxxx>
> > Cc: Brendan Higgins <brendan.higgins@xxxxxxxxx>
> > Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
> > ---
>
> I won't pretend to be a devicetree expert, but this looks good to me
> from a KUnit point of view, and passes comfortably here.
>
> checkpatch seems to have one complaint about the kconfig help text.
> Personally, I think the brief description is fine.
>
> Reviewed-by: David Gow <davidgow@xxxxxxxxxx>
>
Thanks! I noticed that x86 has some devicetree init code. Did you happen
to try on an x86 kvm instance? Or only run on UML?
----8<----
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index afd09924094e..650752d112a6 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -283,22 +283,24 @@ void __init x86_flattree_get_config(void)
u32 size, map_len;
void *dt;
- if (!initial_dtb)
- return;
+ if (initial_dtb) {
+ map_len = max(PAGE_SIZE - (initial_dtb & ~PAGE_MASK), (u64)128);
- map_len = max(PAGE_SIZE - (initial_dtb & ~PAGE_MASK), (u64)128);
+ dt = early_memremap(initial_dtb, map_len);
+ size = fdt_totalsize(dt);
+ if (map_len < size) {
+ early_memunmap(dt, map_len);
+ dt = early_memremap(initial_dtb, size);
+ map_len = size;
+ }
- dt = early_memremap(initial_dtb, map_len);
- size = fdt_totalsize(dt);
- if (map_len < size) {
- early_memunmap(dt, map_len);
- dt = early_memremap(initial_dtb, size);
- map_len = size;
+ early_init_dt_verify(dt);
}
- early_init_dt_verify(dt);
unflatten_and_copy_device_tree();
- early_memunmap(dt, map_len);
+
+ if (initial_dtb)
+ early_memunmap(dt, map_len);
}
#endif
