[PATCH v3 1/7] kho: move fdt setup in separate helper.

Andrey Ryabinin
2025-09-09T20:15:36Z

Move FDT initialization logic from kho_populate() into a new
helper function kho_fdt_init(). The helper takes care of mapping,
validating, and unmapping the FDT.

This prepares for using KSTATE in KHO instead of FDT.

Signed-off-by: Andrey Ryabinin <arbn@yandex-team.com>
---
kernel/liveupdate/kexec_handover.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
index 364a69a2fa1b..e5a436893f5b 100644
--- a/kernel/liveupdate/kexec_handover.c
+++ b/kernel/liveupdate/kexec_handover.c
@@ -1077,13 +1077,10 @@ void __init kho_memory_init(void)
}
}

-void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
- phys_addr_t scratch_phys, u64 scratch_len)
+static int __init kho_fdt_init(phys_addr_t fdt_phys, u64 fdt_len)
{
void *fdt = NULL;
- struct kho_scratch *scratch = NULL;
int err = 0;
- unsigned int scratch_cnt = scratch_len / sizeof(*kho_scratch);

/* Validate the input FDT */
fdt = early_memremap(fdt_phys, fdt_len);
@@ -1107,6 +1104,26 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
goto out;
}

+out:
+ if (fdt)
+ early_memunmap(fdt, fdt_len);
+
+ return err;
+}
+
+void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
+ phys_addr_t scratch_phys, u64 scratch_len)
+{
+
+ struct kho_scratch *scratch = NULL;
+ int err = 0;
+ unsigned int scratch_cnt = scratch_len / sizeof(*kho_scratch);
+
+
+ err = kho_fdt_init(fdt_phys, fdt_len);
+ if (err)
+ goto out;
+
scratch = early_memremap(scratch_phys, scratch_len);
if (!scratch) {
pr_warn("setup: failed to memremap scratch (phys=0x%llx, len=%lld)\n",
@@ -1151,8 +1168,6 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
pr_info("found kexec handover data. Will skip init for some devices\n");

out:
- if (fdt)
- early_memunmap(fdt, fdt_len);
if (scratch)
early_memunmap(scratch, scratch_len);
if (err)
--
2.49.1