s390: Use generic init_task

Same code. Use the generic version. The special Makefile treatment is
pointless anyway as init_task.o contains only data which is handled by
the linker script. So no point on being treated like head text.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Link: http://lkml.kernel.org/r/20120503085035.271439530@linutronix.de

arch/s390/Kconfig

@@ -123,6 +123,7 @@ config S390
 	select ARCH_INLINE_WRITE_UNLOCK_IRQ
 	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
 	select GENERIC_SMP_IDLE_THREAD
+	select HAVE_GENERIC_INIT_TASK
 
 config SCHED_OMIT_FRAME_POINTER
 	def_bool y

arch/s390/Makefile

@@ -91,7 +91,6 @@ OBJCOPYFLAGS	:= -O binary
 
 head-y		:= arch/s390/kernel/head.o
 head-y		+= arch/s390/kernel/$(if $(CONFIG_64BIT),head64.o,head31.o)
-head-y		+= arch/s390/kernel/init_task.o
 
 # See arch/s390/Kbuild for content of core part of the kernel
 core-y		+= arch/s390/

arch/s390/kernel/Makefile

@@ -28,7 +28,7 @@ obj-y	:=  bitmap.o traps.o time.o process.o base.o early.o setup.o vtime.o \
 obj-y	+= $(if $(CONFIG_64BIT),entry64.o,entry.o)
 obj-y	+= $(if $(CONFIG_64BIT),reipl64.o,reipl.o)
 
-extra-y				+= head.o init_task.o vmlinux.lds
+extra-y				+= head.o vmlinux.lds
 extra-y				+= $(if $(CONFIG_64BIT),head64.o,head31.o)
 
 obj-$(CONFIG_MODULES)		+= s390_ksyms.o module.o

arch/s390/kernel/init_task.c

-/*
- *  arch/s390/kernel/init_task.c
- *
- *  S390 version
- *
- *  Derived from "arch/i386/kernel/init_task.c"
- */
-
-#include <linux/mm.h>
-#include <linux/fs.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is THREAD_SIZE aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);