diff --git a/arch/arc/kernel/devtree.c b/arch/arc/kernel/devtree.c
index bdee3a8120521..2340af0e1d6f8 100644
--- a/arch/arc/kernel/devtree.c
+++ b/arch/arc/kernel/devtree.c
@@ -18,12 +18,6 @@
 #include <asm/clk.h>
 #include <asm/mach_desc.h>
 
-/* called from unflatten_device_tree() to bootstrap devicetree itself */
-void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
-{
-	return __va(memblock_alloc(size, align));
-}
-
 /**
  * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
  * @dt:		virtual address pointer to dt blob
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index add6ea6168431..0f9856a2afa42 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -190,11 +190,6 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 	memblock_add(base, size);
 }
 
-void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
-{
-	return __va(memblock_alloc(size, align));
-}
-
 /*
  * Limit the memory size that was specified via FDT.
  */
diff --git a/arch/c6x/kernel/devicetree.c b/arch/c6x/kernel/devicetree.c
index 287d0e64dfba5..9e15ab9199b24 100644
--- a/arch/c6x/kernel/devicetree.c
+++ b/arch/c6x/kernel/devicetree.c
@@ -45,8 +45,3 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 {
 	c6x_add_memory(base, size);
 }
-
-void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
-{
-	return __va(memblock_alloc(size, align));
-}
diff --git a/arch/microblaze/kernel/prom.c b/arch/microblaze/kernel/prom.c
index 62e2e8f2c5d61..0c4453f134cbb 100644
--- a/arch/microblaze/kernel/prom.c
+++ b/arch/microblaze/kernel/prom.c
@@ -46,11 +46,6 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 	memblock_add(base, size);
 }
 
-void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
-{
-	return __va(memblock_alloc(size, align));
-}
-
 #ifdef CONFIG_EARLY_PRINTK
 static char *stdout;
 
diff --git a/arch/openrisc/kernel/prom.c b/arch/openrisc/kernel/prom.c
index 150215a917114..a63e76872f84d 100644
--- a/arch/openrisc/kernel/prom.c
+++ b/arch/openrisc/kernel/prom.c
@@ -55,11 +55,6 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 	memblock_add(base, size);
 }
 
-void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
-{
-	return __va(memblock_alloc(size, align));
-}
-
 void __init early_init_devtree(void *params)
 {
 	void *alloc;
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 67d18dad43688..3fa349efc4a6e 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -544,11 +544,6 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 	memblock_add(base, size);
 }
 
-void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
-{
-	return __va(memblock_alloc(size, align));
-}
-
 #ifdef CONFIG_BLK_DEV_INITRD
 void __init early_init_dt_setup_initrd_arch(u64 start, u64 end)
 {
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index b9657e5304eda..d49b3e8159bb2 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -11,6 +11,7 @@
 
 #include <linux/kernel.h>
 #include <linux/initrd.h>
+#include <linux/memblock.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
@@ -700,6 +701,17 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
 	return 1;
 }
 
+#ifdef CONFIG_HAVE_MEMBLOCK
+/*
+ * called from unflatten_device_tree() to bootstrap devicetree itself
+ * Architectures can override this definition if memblock isn't used
+ */
+void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+	return __va(memblock_alloc(size, align));
+}
+#endif
+
 /**
  * unflatten_device_tree - create tree of device_nodes from flat blob
  *