Subject: [RFC PATCH 11/20] kho: return virtual address of mem_map

From: Jork Loeser <[email-masked]>
Date: Wed, 27 May 2026 17:41:53 -0700

From: "Pratyush Yadav (Google)" <[email-masked]>

There are currently 3 callers of kho_get_mem_map_phys(). Two of them,
kho_mem_retrieve() and kho_extend_scratch() need the virtual address.
The third, kho_populate() doesn't care. Make things simpler by
directly returning the virtual address. Rename kho_get_mem_map_phys() to
kho_get_mem_map() to accurately reflect what it returns.

Signed-off-by: Pratyush Yadav (Google) <[email-masked]>
Signed-off-by: Jork Loeser <[email-masked]>
---
 kernel/liveupdate/kexec_handover.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
index a006a883ee94..797ec285b698 100644
--- a/kernel/liveupdate/kexec_handover.c
+++ b/kernel/liveupdate/kexec_handover.c
@@ -610,10 +610,11 @@ static int __init kho_preserved_memory_reserve(unsigned long key, void *data)
 	return 0;
 }
 
-/* Returns physical address of the preserved memory map from FDT */
-static phys_addr_t __init kho_get_mem_map_phys(const void *fdt)
+/* Returns virtual address of the preserved memory map from FDT */
+static __init void *kho_get_mem_map(const void *fdt)
 {
 	const void *mem_ptr;
+	phys_addr_t mem_map_phys;
 	int len;
 
 	mem_ptr = fdt_getprop(fdt, 0, KHO_FDT_MEMORY_MAP_PROP_NAME, &len);
@@ -622,7 +623,11 @@ static phys_addr_t __init kho_get_mem_map_phys(const void *fdt)
 		return 0;
 	}
 
-	return get_unaligned((const u64 *)mem_ptr);
+	mem_map_phys = get_unaligned((const u64 *)mem_ptr);
+	if (!mem_map_phys)
+		return NULL;
+
+	return phys_to_virt(mem_map_phys);
 }
 
 /*
@@ -917,15 +922,15 @@ void __init kho_extend_scratch(void)
 		.key = kho_ext_mark_scratch,
 	};
 	struct kho_radix_tree radix;
-	phys_addr_t prev_end = 0, mem_map_phys;
+	phys_addr_t prev_end = 0;
 	int err = 0;
 
 	if (!is_kho_boot())
 		return;
 
 	/* Make sure the KHO radix tree is initialized. */
-	mem_map_phys = kho_get_mem_map_phys(kho_get_fdt());
-	err = kho_radix_init_tree(&kho_in.radix_tree, phys_to_virt(mem_map_phys));
+	err = kho_radix_init_tree(&kho_in.radix_tree,
+				  kho_get_mem_map(kho_get_fdt()));
 	if (err)
 		goto print;
 
@@ -1609,11 +1614,9 @@ static int __init kho_mem_retrieve(const void *fdt)
 	const struct kho_radix_walk_cb cb = {
 		.key = kho_preserved_memory_reserve,
 	};
-	phys_addr_t mem_map_phys;
 	int err;
 
-	mem_map_phys = kho_get_mem_map_phys(fdt);
-	err = kho_radix_init_tree(&kho_in.radix_tree, phys_to_virt(mem_map_phys));
+	err = kho_radix_init_tree(&kho_in.radix_tree, kho_get_mem_map(fdt));
 	if (err)
 		return err;
 
@@ -1838,8 +1841,7 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
 {
 	unsigned int scratch_cnt = scratch_len / sizeof(*kho_scratch);
 	struct kho_scratch *scratch = NULL;
-	phys_addr_t mem_map_phys;
-	void *fdt = NULL;
+	void *fdt = NULL, *mem_map;
 	bool populated = false;
 	int err;
 
@@ -1862,8 +1864,8 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
 		goto unmap_fdt;
 	}
 
-	mem_map_phys = kho_get_mem_map_phys(fdt);
-	if (!mem_map_phys)
+	mem_map = kho_get_mem_map(fdt);
+	if (!mem_map)
 		goto unmap_fdt;
 
 	scratch = early_memremap(scratch_phys, scratch_len);
-- 
2.43.0