diff --git a/arch/Kconfig b/arch/Kconfig
index 4cfb6de48f79..d2bf5db0805f 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -245,6 +245,13 @@ config ARCH_HAS_FORTIFY_SOURCE
 	  An architecture should select this when it can successfully
 	  build and run with CONFIG_FORTIFY_SOURCE.
 
+#
+# Select if the arch provides a historic keepinit alias for the retain_initrd
+# command line option
+#
+config ARCH_HAS_KEEPINITRD
+	bool
+
 # Select if arch has all set_memory_ro/rw/x/nx() functions in asm/cacheflush.h
 config ARCH_HAS_SET_MEMORY
 	bool
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 664e918e2624..4c99a29a8ec7 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -8,6 +8,7 @@ config ARM
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
+	select ARCH_HAS_KEEPINITRD
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 478ea8b7db87..d0ccbfab94db 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -752,27 +752,14 @@ void free_initmem(void)
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD
-
-static int keep_initrd;
-
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
-	if (!keep_initrd) {
-		if (start == initrd_start)
-			start = round_down(start, PAGE_SIZE);
-		if (end == initrd_end)
-			end = round_up(end, PAGE_SIZE);
+	if (start == initrd_start)
+		start = round_down(start, PAGE_SIZE);
+	if (end == initrd_end)
+		end = round_up(end, PAGE_SIZE);
 
-		poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
-		free_reserved_area((void *)start, (void *)end, -1, "initrd");
-	}
+	poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
+	free_reserved_area((void *)start, (void *)end, -1, "initrd");
 }
-
-static int __init keepinitrd_setup(char *__unused)
-{
-	keep_initrd = 1;
-	return 1;
-}
-
-__setup("keepinitrd", keepinitrd_setup);
 #endif
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a4168d366127..74c89b628afd 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -19,6 +19,7 @@ config ARM64
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
+	select ARCH_HAS_KEEPINITRD
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_PTE_SPECIAL
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 7205a9085b4d..019c790d8d56 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -622,24 +622,11 @@ void free_initmem(void)
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD
-
-static int keep_initrd __initdata;
-
 void __init free_initrd_mem(unsigned long start, unsigned long end)
 {
-	if (!keep_initrd) {
-		free_reserved_area((void *)start, (void *)end, 0, "initrd");
-		memblock_free(__virt_to_phys(start), end - start);
-	}
-}
-
-static int __init keepinitrd_setup(char *__unused)
-{
-	keep_initrd = 1;
-	return 1;
+	free_reserved_area((void *)start, (void *)end, 0, "initrd");
+	memblock_free(__virt_to_phys(start), end - start);
 }
-
-__setup("keepinitrd", keepinitrd_setup);
 #endif
 
 /*
diff --git a/arch/unicore32/Kconfig b/arch/unicore32/Kconfig
index c3a41bfe161b..b924c11e3ff9 100644
--- a/arch/unicore32/Kconfig
+++ b/arch/unicore32/Kconfig
@@ -2,6 +2,7 @@
 config UNICORE32
 	def_bool y
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
+	select ARCH_HAS_KEEPINITRD
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
 	select HAVE_GENERIC_DMA_COHERENT
diff --git a/arch/unicore32/mm/init.c b/arch/unicore32/mm/init.c
index 85ef2c624090..e3f4f791e10a 100644
--- a/arch/unicore32/mm/init.c
+++ b/arch/unicore32/mm/init.c
@@ -318,20 +318,8 @@ void free_initmem(void)
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD
-
-static int keep_initrd;
-
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
-	if (!keep_initrd)
-		free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-
-static int __init keepinitrd_setup(char *__unused)
-{
-	keep_initrd = 1;
-	return 1;
+	free_reserved_area((void *)start, (void *)end, -1, "initrd");
 }
-
-__setup("keepinitrd", keepinitrd_setup);
 #endif
diff --git a/init/initramfs.c b/init/initramfs.c
index c55e08f72fad..cf8bf014873f 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -513,6 +513,15 @@ static int __init retain_initrd_param(char *str)
 }
 __setup("retain_initrd", retain_initrd_param);
 
+#ifdef CONFIG_ARCH_HAS_KEEPINITRD
+static int __init keepinitrd_setup(char *__unused)
+{
+	do_retain_initrd = 1;
+	return 1;
+}
+__setup("keepinitrd", keepinitrd_setup);
+#endif
+
 extern char __initramfs_start[];
 extern unsigned long __initramfs_size;
 #include <linux/initrd.h>
