initramfs: generalize initramfs_data.xxx.S variants

Remove initramfs_data.{lzo,lzma,gz,bz2}.S variants and use a common
implementation in initramfs_data.S.  The common implementation expects the
file name of the initramfs to be defined in INITRAMFS_IMAGE.

Change the Makefile to set the INITRAMFS_IMAGE define symbol according
to the selected compression method.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Acked-by: Michal Marek <mmarek@suse.cz>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

usr/Makefile

@@ -18,13 +18,15 @@ suffix_$(CONFIG_INITRAMFS_COMPRESSION_LZMA)   = .lzma
 # Lzo
 suffix_$(CONFIG_INITRAMFS_COMPRESSION_LZO)   = .lzo
 
+AFLAGS_initramfs_data.o += -DINITRAMFS_IMAGE="usr/initramfs_data.cpio$(suffix_y)"
+
 # Generate builtin.o based on initramfs_data.o
-obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data$(suffix_y).o
+obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
 
 # initramfs_data.o contains the compressed initramfs_data.cpio image.
 # The image is included using .incbin, a dependency which is not
 # tracked automatically.
-$(obj)/initramfs_data$(suffix_y).o: $(obj)/initramfs_data.cpio$(suffix_y) FORCE
+$(obj)/initramfs_data.o: $(obj)/initramfs_data.cpio$(suffix_y) FORCE
 
 #####
 # Generate the initramfs cpio archive

usr/initramfs_data.S

@@ -25,6 +25,7 @@ SECTIONS
   in the ELF header, as required by certain architectures.
 */
 
-.section .init.ramfs,"a"
-.incbin "usr/initramfs_data.cpio"
+#include <linux/stringify.h>
 
+.section .init.ramfs,"a"
+.incbin __stringify(INITRAMFS_IMAGE)