diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c
index a42fc5c4db89..97f4940f11e3 100644
--- a/arch/alpha/mm/init.c
+++ b/arch/alpha/mm/init.c
@@ -291,11 +291,3 @@ free_initmem(void)
 {
 	free_initmem_default(-1);
 }
-
-#ifdef CONFIG_BLK_DEV_INITRD
-void
-free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index e1ab2d7f1d64..c357a3bd1532 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -214,10 +214,3 @@ void __ref free_initmem(void)
 {
 	free_initmem_default(-1);
 }
-
-#ifdef CONFIG_BLK_DEV_INITRD
-void __init free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
diff --git a/arch/c6x/mm/init.c b/arch/c6x/mm/init.c
index fe582c3a1794..6fd43ec53507 100644
--- a/arch/c6x/mm/init.c
+++ b/arch/c6x/mm/init.c
@@ -69,13 +69,6 @@ void __init mem_init(void)
 	mem_init_print_info(NULL);
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void __init free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
-
 void __init free_initmem(void)
 {
 	free_initmem_default(-1);
diff --git a/arch/h8300/mm/init.c b/arch/h8300/mm/init.c
index 0f04a5e9aa4f..ea635c9025fe 100644
--- a/arch/h8300/mm/init.c
+++ b/arch/h8300/mm/init.c
@@ -103,14 +103,6 @@ void __init mem_init(void)
 	mem_init_print_info(NULL);
 }
 
-
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
-
 void
 free_initmem(void)
 {
diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c
index 8868a4c9adae..778cacb7d57b 100644
--- a/arch/m68k/mm/init.c
+++ b/arch/m68k/mm/init.c
@@ -147,10 +147,3 @@ void __init mem_init(void)
 	init_pointer_tables();
 	mem_init_print_info(NULL);
 }
-
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
index 7e97d44f6538..b675bc666e68 100644
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c
@@ -186,13 +186,6 @@ void __init setup_memory(void)
 	paging_init();
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
-
 void free_initmem(void)
 {
 	free_initmem_default(-1);
diff --git a/arch/nds32/mm/init.c b/arch/nds32/mm/init.c
index 1d03633f89a9..9a7065c1fb83 100644
--- a/arch/nds32/mm/init.c
+++ b/arch/nds32/mm/init.c
@@ -257,13 +257,6 @@ void free_initmem(void)
 	free_initmem_default(-1);
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
-
 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 16cea5776b87..60736a725883 100644
--- a/arch/nios2/mm/init.c
+++ b/arch/nios2/mm/init.c
@@ -82,13 +82,6 @@ void __init mmu_init(void)
 	flush_tlb_all();
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void __init free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
-
 void __ref free_initmem(void)
 {
 	free_initmem_default(-1);
diff --git a/arch/openrisc/mm/init.c b/arch/openrisc/mm/init.c
index caeb4184e8a6..08df7f0b1d96 100644
--- a/arch/openrisc/mm/init.c
+++ b/arch/openrisc/mm/init.c
@@ -224,13 +224,6 @@ void __init mem_init(void)
 	return;
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
-
 void free_initmem(void)
 {
 	free_initmem_default(-1);
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index 3b0f9eab7f2c..11ec1f1221a6 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -917,10 +917,3 @@ void flush_tlb_all(void)
 	spin_unlock(&sid_lock);
 }
 #endif
-
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index cd525d709072..20266898f3a8 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -338,13 +338,6 @@ void free_initmem(void)
 	free_initmem_default(POISON_FREE_INITMEM);
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void __init free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
-
 /*
  * This is called when a page has been modified by the kernel.
  * It just marks the page as not i-cache clean.  We do the i-cache
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 70621324db41..3e68d98af1bd 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -408,13 +408,6 @@ void free_initmem(void)
 	free_initmem_default(-1);
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
-
 #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/um/kernel/mem.c b/arch/um/kernel/mem.c
index 99aa11bf53d1..a9c9a94c096f 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -188,13 +188,6 @@ void free_initmem(void)
 {
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
-
 /* Allocate and free page tables. */
 
 pgd_t *pgd_alloc(struct mm_struct *mm)
diff --git a/arch/unicore32/mm/init.c b/arch/unicore32/mm/init.c
index c0573feb5064..6e352de80038 100644
--- a/arch/unicore32/mm/init.c
+++ b/arch/unicore32/mm/init.c
@@ -292,10 +292,3 @@ void free_initmem(void)
 {
 	free_initmem_default(-1);
 }
-
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
diff --git a/init/initramfs.c b/init/initramfs.c
index cb3d17735c66..fcb759a106be 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -527,6 +527,11 @@ extern unsigned long __initramfs_size;
 #include <linux/initrd.h>
 #include <linux/kexec.h>
 
+void __weak free_initrd_mem(unsigned long start, unsigned long end)
+{
+	free_reserved_area((void *)start, (void *)end, -1, "initrd");
+}
+
 #ifdef CONFIG_KEXEC_CORE
 static bool kexec_free_initrd(void)
 {