diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c
index 97f4940f11e3..e2cbec3789e8 100644
--- a/arch/alpha/mm/init.c
+++ b/arch/alpha/mm/init.c
@@ -285,9 +285,3 @@ mem_init(void)
 	memblock_free_all();
 	mem_init_print_info(NULL);
 }
-
-void
-free_initmem(void)
-{
-	free_initmem_default(-1);
-}
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index c357a3bd1532..02b7a3b20d7c 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -206,11 +206,3 @@ void __init mem_init(void)
 	memblock_free_all();
 	mem_init_print_info(NULL);
 }
-
-/*
- * free_initmem: Free all the __init memory.
- */
-void __ref free_initmem(void)
-{
-	free_initmem_default(-1);
-}
diff --git a/arch/c6x/mm/init.c b/arch/c6x/mm/init.c
index 6fd43ec53507..573242b160e1 100644
--- a/arch/c6x/mm/init.c
+++ b/arch/c6x/mm/init.c
@@ -68,8 +68,3 @@ void __init mem_init(void)
 
 	mem_init_print_info(NULL);
 }
-
-void __init free_initmem(void)
-{
-	free_initmem_default(-1);
-}
diff --git a/arch/h8300/mm/init.c b/arch/h8300/mm/init.c
index ea635c9025fe..1eab16b1a0bc 100644
--- a/arch/h8300/mm/init.c
+++ b/arch/h8300/mm/init.c
@@ -102,9 +102,3 @@ void __init mem_init(void)
 
 	mem_init_print_info(NULL);
 }
-
-void
-free_initmem(void)
-{
-	free_initmem_default(-1);
-}
diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
index b675bc666e68..a015a951c8b7 100644
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c
@@ -186,11 +186,6 @@ void __init setup_memory(void)
 	paging_init();
 }
 
-void free_initmem(void)
-{
-	free_initmem_default(-1);
-}
-
 void __init mem_init(void)
 {
 	high_memory = (void *)__va(memory_start + lowmem_size - 1);
diff --git a/arch/nds32/mm/init.c b/arch/nds32/mm/init.c
index 9a7065c1fb83..1a4ab1b7525f 100644
--- a/arch/nds32/mm/init.c
+++ b/arch/nds32/mm/init.c
@@ -252,11 +252,6 @@ void __init mem_init(void)
 	return;
 }
 
-void free_initmem(void)
-{
-	free_initmem_default(-1);
-}
-
 void __set_fixmap(enum fixed_addresses idx,
 			       phys_addr_t phys, pgprot_t flags)
 {
diff --git a/arch/nios2/mm/init.c b/arch/nios2/mm/init.c
index 60736a725883..2c609c2516b2 100644
--- a/arch/nios2/mm/init.c
+++ b/arch/nios2/mm/init.c
@@ -82,11 +82,6 @@ void __init mmu_init(void)
 	flush_tlb_all();
 }
 
-void __ref free_initmem(void)
-{
-	free_initmem_default(-1);
-}
-
 #define __page_aligned(order) __aligned(PAGE_SIZE << (order))
 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);
diff --git a/arch/openrisc/mm/init.c b/arch/openrisc/mm/init.c
index 08df7f0b1d96..abe87e54e231 100644
--- a/arch/openrisc/mm/init.c
+++ b/arch/openrisc/mm/init.c
@@ -223,8 +223,3 @@ void __init mem_init(void)
 	mem_init_done = 1;
 	return;
 }
-
-void free_initmem(void)
-{
-	free_initmem_default(-1);
-}
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 3e68d98af1bd..aeb9f45c7a39 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -403,11 +403,6 @@ void __init mem_init(void)
 	mem_init_done = 1;
 }
 
-void free_initmem(void)
-{
-	free_initmem_default(-1);
-}
-
 #ifdef CONFIG_MEMORY_HOTPLUG
 int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
 		bool want_memblock)
diff --git a/arch/unicore32/mm/init.c b/arch/unicore32/mm/init.c
index 6e352de80038..b4442f3060ce 100644
--- a/arch/unicore32/mm/init.c
+++ b/arch/unicore32/mm/init.c
@@ -287,8 +287,3 @@ void __init mem_init(void)
 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 	}
 }
-
-void free_initmem(void)
-{
-	free_initmem_default(-1);
-}
diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index d49861099684..b51746f2b80b 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -216,11 +216,6 @@ void free_initrd_mem(unsigned long start, unsigned long end)
 }
 #endif
 
-void free_initmem(void)
-{
-	free_initmem_default(-1);
-}
-
 static void __init parse_memmap_one(char *p)
 {
 	char *oldp;
diff --git a/init/main.c b/init/main.c
index 33c87e91dc37..26234570a324 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1074,6 +1074,11 @@ static inline void mark_readonly(void)
 }
 #endif
 
+void __weak free_initmem(void)
+{
+	free_initmem_default(-1);
+}
+
 static int __ref kernel_init(void *unused)
 {
 	int ret;