s390: remove 31 bit support

Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.

The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.

Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index acb6859..667b1bca 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -13,15 +13,6 @@
 # Copyright (C) 1994 by Linus Torvalds
 #
 
-ifndef CONFIG_64BIT
-LD_BFD		:= elf32-s390
-LDFLAGS		:= -m elf_s390
-KBUILD_CFLAGS	+= -m31
-KBUILD_AFLAGS	+= -m31
-UTS_MACHINE	:= s390
-STACK_SIZE	:= 8192
-CHECKFLAGS	+= -D__s390__ -msize-long
-else
 LD_BFD		:= elf64-s390
 LDFLAGS		:= -m elf64_s390
 KBUILD_AFLAGS_MODULE += -fPIC
@@ -31,11 +22,9 @@
 UTS_MACHINE	:= s390x
 STACK_SIZE	:= 16384
 CHECKFLAGS	+= -D__s390__ -D__s390x__
-endif
 
 export LD_BFD
 
-mflags-$(CONFIG_MARCH_G5)     := -march=g5
 mflags-$(CONFIG_MARCH_Z900)   := -march=z900
 mflags-$(CONFIG_MARCH_Z990)   := -march=z990
 mflags-$(CONFIG_MARCH_Z9_109) := -march=z9-109
@@ -47,7 +36,6 @@
 aflags-y += $(mflags-y)
 cflags-y += $(mflags-y)
 
-cflags-$(CONFIG_MARCH_G5_TUNE)		+= -mtune=g5
 cflags-$(CONFIG_MARCH_Z900_TUNE)	+= -mtune=z900
 cflags-$(CONFIG_MARCH_Z990_TUNE)	+= -mtune=z990
 cflags-$(CONFIG_MARCH_Z9_109_TUNE)	+= -mtune=z9-109
@@ -104,7 +92,7 @@
 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/head64.o
 
 # See arch/s390/Kbuild for content of core part of the kernel
 core-y		+= arch/s390/
@@ -129,9 +117,7 @@
 	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
 
 vdso_install:
-ifeq ($(CONFIG_64BIT),y)
 	$(Q)$(MAKE) $(build)=arch/$(ARCH)/kernel/vdso64 $@
-endif
 	$(Q)$(MAKE) $(build)=arch/$(ARCH)/kernel/vdso32 $@
 
 archclean: