[PATCH v3 4/7] x86/of: Unconditionally call unflatten_and_copy_device_tree()

From: Stephen Boyd
Date: Fri Feb 02 2024 - 15:00:21 EST


Call this function unconditionally so that we can populate an empty DTB
on platforms that don't boot with a firmware provided or builtin DTB.
There's no harm in calling unflatten_device_tree() unconditionally here.
If there isn't a non-NULL 'initial_boot_params' pointer then
unflatten_device_tree() returns early.

Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Frank Rowand <frowand.list@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: <x86@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
---
arch/x86/kernel/devicetree.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)

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

--
https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/
https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git