initramfs: move the legacy keepinitrd parameter to core code

No need to handle the freeing disable in arch code when we already have a
core hook (and a different name for the option) for it.

Link: http://lkml.kernel.org/r/20190213174621.29297-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Steven Price <steven.price@arm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/Kconfig b/arch/Kconfig
index 5e43fcb..f11f069 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -245,6 +245,13 @@
 	  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 dc9855c..a11dfcc 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -9,6 +9,7 @@
 	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 c2daabb..68dcd5f 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -695,27 +695,14 @@ 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 3f95744..e24dc16 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -21,6 +21,7 @@
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
+	select ARCH_HAS_KEEPINITRD
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SETUP_DMA_OPS
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 40e2d7e..007c05a 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -578,24 +578,11 @@ 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);
-	}
+	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;
-}
-
-__setup("keepinitrd", keepinitrd_setup);
 #endif
 
 /*
diff --git a/arch/unicore32/Kconfig b/arch/unicore32/Kconfig
index 2445dfc..afe4949 100644
--- a/arch/unicore32/Kconfig
+++ b/arch/unicore32/Kconfig
@@ -3,6 +3,7 @@
 	def_bool y
 	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
+	select ARCH_HAS_KEEPINITRD
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
 	select HAVE_KERNEL_GZIP
diff --git a/arch/unicore32/mm/init.c b/arch/unicore32/mm/init.c
index 74b6a2e..c0573fe 100644
--- a/arch/unicore32/mm/init.c
+++ b/arch/unicore32/mm/init.c
@@ -294,20 +294,8 @@ 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");
+	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