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.deSigned-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>

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

arch/arm/Kconfig

@@ -9,6 +9,7 @@ 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

arch/arm/mm/init.c

@@ -695,12 +695,8 @@ 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) {
 	if (start == initrd_start)
 		start = round_down(start, PAGE_SIZE);
 	if (end == initrd_end)
@@ -708,14 +704,5 @@ void free_initrd_mem(unsigned long start, unsigned long end)
 
 	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

arch/arm64/Kconfig

@@ -21,6 +21,7 @@ config ARM64
 	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

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);
-	}
-}
-
-static int __init keepinitrd_setup(char *__unused)
-{
-	keep_initrd = 1;
-	return 1;
 }
-
-__setup("keepinitrd", keepinitrd_setup);
 #endif
 
 /*

arch/unicore32/Kconfig

@@ -3,6 +3,7 @@ config UNICORE32
 	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

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");
 }
-
-static int __init keepinitrd_setup(char *__unused)
-{
-	keep_initrd = 1;
-	return 1;
-}
-
-__setup("keepinitrd", keepinitrd_setup);
 #endif

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>