Re: [PATCH 6/6] of: Add KUnit test to confirm DTB is loaded
From: Stephen Boyd <sboyd@kernel.org>
Date: 2024-01-22 22:48:06
Also in:
linux-arm-kernel, linux-kselftest, linux-patches, linux-um, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Quoting David Gow (2024-01-15 21:03:12)
On Sat, 13 Jan 2024 at 04:07, Stephen Boyd [off-list ref] wrote:quoted
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@kernel.org> Cc: Frank Rowand <redacted> Cc: David Gow <redacted> Cc: Brendan Higgins <brendan.higgins@linux.dev> Signed-off-by: Stephen Boyd <sboyd@kernel.org> ---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 <redacted>
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