arm64: efi: Move efi-entry.S into the libstub source directory

We will be sharing efi-entry.S with the zboot decompressor build, which
does not link against vmlinux directly. So move it into the libstub
source directory so we can include in the libstub static library.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/Makefile

@@ -36,12 +36,6 @@ obj-y			:= debug-monitors.o entry.o irq.o fpsimd.o		\
 			   syscall.o proton-pack.o idreg-override.o idle.o	\
 			   patching.o
 
-targets			+= efi-entry.o
-
-OBJCOPYFLAGS := --prefix-symbols=__efistub_
-$(obj)/%.stub.o: $(obj)/%.o FORCE
-	$(call if_changed,objcopy)
-
 obj-$(CONFIG_COMPAT)			+= sys32.o signal32.o			\
 					   sys_compat.o
 obj-$(CONFIG_COMPAT)			+= sigreturn32.o
@@ -57,8 +51,7 @@ obj-$(CONFIG_CPU_PM)			+= sleep.o suspend.o
 obj-$(CONFIG_CPU_IDLE)			+= cpuidle.o
 obj-$(CONFIG_JUMP_LABEL)		+= jump_label.o
 obj-$(CONFIG_KGDB)			+= kgdb.o
-obj-$(CONFIG_EFI)			+= efi.o efi-entry.stub.o		\
-					   efi-rt-wrapper.o
+obj-$(CONFIG_EFI)			+= efi.o efi-rt-wrapper.o
 obj-$(CONFIG_PCI)			+= pci.o
 obj-$(CONFIG_ARMV8_DEPRECATED)		+= armv8_deprecated.o
 obj-$(CONFIG_ACPI)			+= acpi.o

drivers/firmware/efi/libstub/Makefile

@@ -83,7 +83,7 @@ $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
 lib-$(CONFIG_EFI_GENERIC_STUB)	+= efi-stub.o string.o intrinsics.o systable.o
 
 lib-$(CONFIG_ARM)		+= arm32-stub.o
-lib-$(CONFIG_ARM64)		+= arm64-stub.o
+lib-$(CONFIG_ARM64)		+= arm64-stub.o arm64-entry.o
 lib-$(CONFIG_X86)		+= x86-stub.o
 lib-$(CONFIG_RISCV)		+= riscv-stub.o
 lib-$(CONFIG_LOONGARCH)		+= loongarch-stub.o
@@ -137,7 +137,7 @@ STUBCOPY_RELOC-$(CONFIG_ARM)	:= R_ARM_ABS
 #
 STUBCOPY_FLAGS-$(CONFIG_ARM64)	+= --prefix-alloc-sections=.init \
 				   --prefix-symbols=__efistub_
-STUBCOPY_RELOC-$(CONFIG_ARM64)	:= R_AARCH64_ABS
+STUBCOPY_RELOC-$(CONFIG_ARM64)	:= R_AARCH64_ABS64
 
 # For RISC-V, we don't need anything special other than arm64. Keep all the
 # symbols in .init section and make sure that no absolute symbols references

arch/arm64/kernel/efi-entry.S → drivers/firmware/efi/libstub/arm64-entry.S

@@ -6,12 +6,8 @@
  * Author: Mark Salter <msalter@redhat.com>
  */
 #include <linux/linkage.h>
-#include <linux/init.h>
-
 #include <asm/assembler.h>
 
-	__INIT
-
 SYM_CODE_START(efi_enter_kernel)
 	/*
 	 * efi_pe_entry() will have copied the kernel image if necessary and we