kbuild: require all architectures to have arch/$(SRCARCH)/Kbuild

arch/$(SRCARCH)/Kbuild is useful for Makefile cleanups because you can
use the obj-y syntax.

Add an empty file if it is missing in arch/$(SRCARCH)/.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Makefile

@@ -658,7 +658,7 @@ endif
 
 ifeq ($(KBUILD_EXTMOD),)
 # Objects we will link into vmlinux / subdirs we need to visit
-core-y		:= init/ usr/
+core-y		:= init/ usr/ arch/$(SRCARCH)/
 drivers-y	:= drivers/ sound/
 drivers-$(CONFIG_SAMPLES) += samples/
 drivers-$(CONFIG_NET) += net/

arch/alpha/Kbuild

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-only

arch/arc/Makefile

@@ -85,9 +85,6 @@ KBUILD_LDFLAGS	+= $(ldflags-y)
 
 head-y		:= arch/arc/kernel/head.o
 
-# See arch/arc/Kbuild for content of core part of the kernel
-core-y		+= arch/arc/
-
 # w/o this dtb won't embed into kernel binary
 core-y		+= arch/arc/boot/dts/
 

arch/arm/Makefile

@@ -252,7 +252,6 @@ endif
 
 export	TEXT_OFFSET GZFLAGS MMUEXT
 
-core-y				+= arch/arm/
 # If we have a machine-specific directory, then include it in the build.
 core-y				+= $(machdirs) $(platdirs)
 

arch/arm64/Makefile

@@ -149,7 +149,6 @@ KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
 KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
 KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
 
-core-y		+= arch/arm64/
 libs-y		:= arch/arm64/lib/ $(libs-y)
 libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
 

arch/csky/Kbuild

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-only

arch/h8300/Kbuild

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-only

arch/hexagon/Kbuild

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-only

arch/ia64/Kbuild

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-only

arch/m68k/Makefile

@@ -98,7 +98,6 @@ head-$(CONFIG_SUN3)		:= arch/m68k/kernel/sun3-head.o
 head-$(CONFIG_M68000)		:= arch/m68k/68000/head.o
 head-$(CONFIG_COLDFIRE)		:= arch/m68k/coldfire/head.o
 
-core-y				+= arch/m68k/
 libs-y				+= arch/m68k/lib/
 
 

arch/microblaze/Kbuild

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-only

arch/mips/Makefile

@@ -332,9 +332,6 @@ head-y := arch/mips/kernel/head.o
 libs-y			+= arch/mips/lib/
 libs-$(CONFIG_MIPS_FP_SUPPORT) += arch/mips/math-emu/
 
-# See arch/mips/Kbuild for content of core part of the kernel
-core-y += arch/mips/
-
 drivers-y			+= arch/mips/crypto/
 
 # suspend and hibernation support

arch/nds32/Kbuild

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-only

arch/nios2/Kbuild

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-only

arch/openrisc/Makefile

@@ -42,7 +42,6 @@ endif
 
 head-y 		:= arch/openrisc/kernel/head.o
 
-core-y		+= arch/openrisc/
 libs-y		+= $(LIBGCC)
 
 PHONY += vmlinux.bin

arch/parisc/Kbuild

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-only

arch/powerpc/Makefile

@@ -267,9 +267,6 @@ head-$(CONFIG_PPC_FPU)		+= arch/powerpc/kernel/fpu.o
 head-$(CONFIG_ALTIVEC)		+= arch/powerpc/kernel/vector.o
 head-$(CONFIG_PPC_OF_BOOT_TRAMPOLINE)  += arch/powerpc/kernel/prom_init.o
 
-# See arch/powerpc/Kbuild for content of core part of the kernel
-core-y += arch/powerpc/
-
 # Default to zImage, override when needed
 all: zImage
 

arch/riscv/Makefile

@@ -90,7 +90,6 @@ endif
 
 head-y := arch/riscv/kernel/head.o
 
-core-y += arch/riscv/
 core-$(CONFIG_RISCV_ERRATA_ALTERNATIVE) += arch/riscv/errata/
 
 libs-y += arch/riscv/lib/

arch/s390/Makefile

@@ -128,9 +128,6 @@ OBJCOPYFLAGS	:= -O binary
 
 head-y		:= arch/s390/kernel/head64.o
 
-# See arch/s390/Kbuild for content of core part of the kernel
-core-y		+= arch/s390/
-
 libs-y		+= arch/s390/lib/
 drivers-y	+= drivers/s390/
 

arch/sh/Kbuild

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-only

arch/sparc/Makefile

@@ -58,9 +58,6 @@ endif
 
 head-y                 := arch/sparc/kernel/head_$(BITS).o
 
-# See arch/sparc/Kbuild for the core part of the kernel
-core-y                 += arch/sparc/
-
 libs-y                 += arch/sparc/prom/
 libs-y                 += arch/sparc/lib/
 

arch/um/Kbuild

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-only

arch/x86/Makefile

@@ -239,9 +239,6 @@ head-y += arch/x86/kernel/platform-quirks.o
 
 libs-y  += arch/x86/lib/
 
-# See arch/x86/Kbuild for content of core part of the kernel
-core-y += arch/x86/
-
 # drivers-y are linked after core-y
 drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
 drivers-$(CONFIG_PCI)            += arch/x86/pci/

arch/xtensa/Kbuild

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-only