x86: unification of arch/x86/Makefiles

Unify the 32 and 64 bit specific Makefiles.
The unification was simplest to do in one step although the
readability of the patch suffers a bit from this.

Noteworthy remarks on the unification:
- The 64 bit cpu stuff should be moved to Makefile_32.cpu
  but I did not feel confident doing it due to subtle differences
- The use of cflags-y were abandoned since we have seen one bug where
  we did wrong due to missing assignment to KBUILD_CFLAGS.
  The cc-option marcro uses KBUILD_CFLAGS.
- The "No need to remake" line are deleted. It caused "make -B" to fail
- For 64 bit the sub architecture stuff is not used.
- The way head64.o is specified could be nicer - but it awaits the
  introduction of head32.o (which seems like a win to introduce for readability)
- Patch is checkpatch clean

Patch is tested by doing a defconfig build for i386 and x86_64 and in both
cases monitoring that only relevant files were recompiled when applying
the patch.

[ mingo@elte.hu: build fix ]

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/Makefile

@@ -7,13 +7,242 @@ else
         KBUILD_DEFCONFIG := $(ARCH)_defconfig
 endif
 
-# No need to remake these files
-$(srctree)/arch/x86/Makefile%: ;
+# BITS is used as extension for files which are available in a 32 bit
+# and a 64 bit version to simplify shared Makefiles.
+# e.g.: obj-y += foo_$(BITS).o
+export BITS
 
 ifeq ($(CONFIG_X86_32),y)
+        BITS := 32
         UTS_MACHINE := i386
-        include $(srctree)/arch/x86/Makefile_32
+
+        HAS_BIARCH := $(call cc-option-yn, -m32)
+        ifeq ($(HAS_BIARCH),y)
+                AS := $(AS) --32
+                LD := $(LD) -m elf_i386
+                CC := $(CC) -m32
+        endif
+
+        ifdef CONFIG_RELOCATABLE
+                LDFLAGS_vmlinux := --emit-relocs
+        endif
+        CHECKFLAGS += -D__i386__
+
+        KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
+
+        # prevent gcc from keeping the stack 16 byte aligned
+        KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2)
+
+        # Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
+        # a lot more stack due to the lack of sharing of stacklots:
+        KBUILD_CFLAGS += $(shell if [ $(call cc-version) -lt 0400 ] ; then \
+                echo $(call cc-option,-fno-unit-at-a-time); fi ;)
+
+        # CPU-specific tuning. Anything which can be shared with UML should go here.
+        include $(srctree)/arch/x86/Makefile_32.cpu
+        KBUILD_CFLAGS += $(cflags-y)
+
+        # temporary until string.h is fixed
+        KBUILD_CFLAGS += -ffreestanding
 else
+        BITS := 64
         UTS_MACHINE := x86_64
-        include $(srctree)/arch/x86/Makefile_64
+        CHECKFLAGS += -D__x86_64__ -m64
+
+        KBUILD_AFLAGS += -m64
+        KBUILD_CFLAGS += -m64
+
+        # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
+        cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
+        cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
+
+        cflags-$(CONFIG_MCORE2) += \
+                $(call cc-option,-march=core2,$(call cc-option,-mtune=generic))
+        cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic)
+        KBUILD_CFLAGS += $(cflags-y)
+
+        KBUILD_CFLAGS += -mno-red-zone
+        KBUILD_CFLAGS += -mcmodel=kernel
+
+        KBUILD_CFLAGS += -Wno-sign-compare
+        KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
+        # -funit-at-a-time shrinks the kernel .text considerably
+        # unfortunately it makes reading oopses harder.
+        KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
+
+        # prevent gcc from generating any FP code by mistake
+        KBUILD_CFLAGS += $(call cc-option,-mno-sse -mno-mmx -mno-sse2 -mno-3dnow,)
+        # this works around some issues with generating unwind tables in older gccs
+        # newer gccs do it by default
+        KBUILD_CFLAGS += -maccumulate-outgoing-args
+
+        stackp := $(CONFIG_SHELL) $(srctree)/scripts/gcc-x86_64-has-stack-protector.sh
+        stackp-$(CONFIG_CC_STACKPROTECTOR) := $(shell $(stackp) \
+                "$(CC)" -fstack-protector )
+        stackp-$(CONFIG_CC_STACKPROTECTOR_ALL) += $(shell $(stackp) \
+                "$(CC)" -fstack-protector-all )
+
+        KBUILD_CFLAGS += $(stackp-y)
+endif
+
+# Stackpointer is addressed different for 32 bit and 64 bit x86
+sp-$(CONFIG_X86_32) := esp
+sp-$(CONFIG_X86_64) := rsp
+
+# do binutils support CFI?
+cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1)
+# is .cfi_signal_frame supported too?
+cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1)
+KBUILD_AFLAGS += $(cfi) $(cfi-sigframe)
+KBUILD_CFLAGS += $(cfi) $(cfi-sigframe)
+
+LDFLAGS := -m elf_$(UTS_MACHINE)
+OBJCOPYFLAGS := -O binary -R .note -R .comment -S
+KBUILD_CFLAGS += -pipe
+
+###
+# Sub architecture support
+# fcore-y is linked before mcore-y files.
+
+# Default subarch .c files
+mcore-y  := arch/x86/mach-default/
+
+# Voyager subarch support
+mflags-$(CONFIG_X86_VOYAGER)	:= -Iinclude/asm-x86/mach-voyager
+mcore-$(CONFIG_X86_VOYAGER)	:= arch/x86/mach-voyager/
+
+# VISWS subarch support
+mflags-$(CONFIG_X86_VISWS)	:= -Iinclude/asm-x86/mach-visws
+mcore-$(CONFIG_X86_VISWS)	:= arch/x86/mach-visws/
+
+# NUMAQ subarch support
+mflags-$(CONFIG_X86_NUMAQ)	:= -Iinclude/asm-x86/mach-numaq
+mcore-$(CONFIG_X86_NUMAQ)	:= arch/x86/mach-default/
+
+# BIGSMP subarch support
+mflags-$(CONFIG_X86_BIGSMP)	:= -Iinclude/asm-x86/mach-bigsmp
+mcore-$(CONFIG_X86_BIGSMP)	:= arch/x86/mach-default/
+
+#Summit subarch support
+mflags-$(CONFIG_X86_SUMMIT)	:= -Iinclude/asm-x86/mach-summit
+mcore-$(CONFIG_X86_SUMMIT)	:= arch/x86/mach-default/
+
+# generic subarchitecture
+mflags-$(CONFIG_X86_GENERICARCH):= -Iinclude/asm-x86/mach-generic
+fcore-$(CONFIG_X86_GENERICARCH)	+= arch/x86/mach-generic/
+mcore-$(CONFIG_X86_GENERICARCH)	:= arch/x86/mach-default/
+
+
+# ES7000 subarch support
+mflags-$(CONFIG_X86_ES7000)	:= -Iinclude/asm-x86/mach-es7000
+fcore-$(CONFIG_X86_ES7000)	:= arch/x86/mach-es7000/
+mcore-$(CONFIG_X86_ES7000)	:= arch/x86/mach-default/
+
+# default subarch .h files
+mflags-y += -Iinclude/asm-x86/mach-default
+
+# 64 bit does not support subarch support - clear sub arch variables
+fcore-$(CONFIG_X86_64)  :=
+mcore-$(CONFIG_X86_64)  :=
+mflags-$(CONFIG_X86_64) :=
+
+KBUILD_CFLAGS += $(mflags-y)
+KBUILD_AFLAGS += $(mflags-y)
+
+###
+# Kernel objects
+
+head-y                := arch/x86/kernel/head_$(BITS).o
+head-$(CONFIG_X86_64) += arch/x86/kernel/head64.o
+head-y                += arch/x86/kernel/init_task.o
+
+libs-y  += arch/x86/lib/
+
+# Sub architecture files that needs linking first
+core-y += $(fcore-y)
+
+# Xen paravirtualization support
+core-$(CONFIG_XEN) += arch/x86/xen/
+
+# lguest paravirtualization support
+core-$(CONFIG_LGUEST_GUEST) += arch/x86/lguest/
+
+core-y += arch/x86/kernel/
+core-y += arch/x86/mm/
+
+# Remaining sub architecture files
+core-y += $(mcore-y)
+
+core-y += arch/x86/crypto/
+core-y += arch/x86/vdso/
+core-$(CONFIG_IA32_EMULATION) += arch/x86/ia32/
+
+# drivers-y are linked after core-y
+drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
+drivers-$(CONFIG_PCI)            += arch/x86/pci/
+
+# must be linked after kernel/
+drivers-$(CONFIG_OPROFILE) += arch/x86/oprofile/
+
+ifeq ($(CONFIG_X86_32),y)
+drivers-$(CONFIG_PM) += arch/x86/power/
+drivers-$(CONFIG_FB) += arch/x86/video/
 endif
+
+####
+# boot loader support. Several targets are kept for legacy purposes
+
+boot := arch/x86/boot
+
+PHONY += zImage bzImage compressed zlilo bzlilo \
+         zdisk bzdisk fdimage fdimage144 fdimage288 isoimage install
+
+# Default kernel to build
+all: bzImage
+
+# KBUILD_IMAGE specify target image being built
+                    KBUILD_IMAGE := $(boot)/bzImage
+zImage zlilo zdisk: KBUILD_IMAGE := arch/x86/boot/zImage
+
+zImage bzImage: vmlinux
+	$(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
+	$(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
+	$(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/bzImage
+
+compressed: zImage
+
+zlilo bzlilo: vmlinux
+	$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(KBUILD_IMAGE) zlilo
+
+zdisk bzdisk: vmlinux
+	$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(KBUILD_IMAGE) zdisk
+
+fdimage fdimage144 fdimage288 isoimage: vmlinux
+	$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(KBUILD_IMAGE) $@
+
+install: vdso_install
+	$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(KBUILD_IMAGE) install
+
+PHONY += vdso_install
+vdso_install:
+	$(Q)$(MAKE) $(build)=arch/x86/vdso $@
+
+archclean:
+	$(Q)rm -rf $(objtree)/arch/i386
+	$(Q)rm -rf $(objtree)/arch/x86_64
+	$(Q)$(MAKE) $(clean)=$(boot)
+
+define archhelp
+  echo  '* bzImage	- Compressed kernel image (arch/x86/boot/bzImage)'
+  echo  '  install	- Install kernel using'
+  echo  '		   (your) ~/bin/installkernel or'
+  echo  '		   (distribution) /sbin/installkernel or'
+  echo  '		   install to $$(INSTALL_PATH) and run lilo'
+  echo  '  bzdisk       - Create a boot floppy in /dev/fd0'
+  echo  '  fdimage      - Create a boot floppy image'
+  echo  '  isoimage     - Create a boot CD-ROM image'
+endef
+
+CLEAN_FILES += arch/x86/boot/fdimage \
+	       arch/x86/boot/image.iso \
+	       arch/x86/boot/mtools.conf