powerpc: Pass correct CPU reference to assembler

commit 1c922cd3f606577a621716c98ffd7af00cda8055 upstream.

Jan-Benedict reported issue with building ppc64e_defconfig
with mainline GCC work:

  powerpc64-linux-gcc -Wp,-MMD,arch/powerpc/kernel/vdso/.gettimeofday-64.o.d -nostdinc -I./arch/powerpc/include -I./arch/powerpc/include/generated  -I./include -I./arch/powerpc/include/uapi -I./arch/powerpc/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h -D__KERNEL__ -I ./arch/powerpc -DHAVE_AS_ATHIGH=1 -fmacro-prefix-map=./= -D__ASSEMBLY__ -fno-PIE -m64 -Wl,-a64 -mabi=elfv1 -Wa,-me500 -Wa,-me500mc -mabi=elfv1 -mbig-endian    -Wl,-soname=linux-vdso64.so.1 -D__VDSO64__ -s -c -o arch/powerpc/kernel/vdso/gettimeofday-64.o arch/powerpc/kernel/vdso/gettimeofday.S
	arch/powerpc/kernel/vdso/gettimeofday.S: Assembler messages:
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `stdu'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `stdu'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `std'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `std'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `ld'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `ld'
	...
	make[1]: *** [arch/powerpc/kernel/vdso/Makefile:76: arch/powerpc/kernel/vdso/gettimeofday-64.o] Error 1
	make: *** [arch/powerpc/Makefile:387: vdso_prepare] Error 2

This is due to assembler being called with -me500mc which is
a 32 bits target.

The problem comes from the fact that CONFIG_PPC_E500MC is selected for
both the e500mc (32 bits) and the e5500 (64 bits), and therefore the
following makefile rule is wrong:

  cpu-as-$(CONFIG_PPC_E500MC)    += $(call as-option,-Wa$(comma)-me500mc)

Today we have CONFIG_TARGET_CPU which provides the identification of the
expected CPU, it is used for GCC. Once GCC knows the target CPU, it adds
the correct CPU option to assembler, no need to add it explicitly.

With that change (And also commit a950ad8b66d5 ("powerpc/64: Set default
CPU in Kconfig")), it now is:

  powerpc64-linux-gcc -Wp,-MMD,arch/powerpc/kernel/vdso/.gettimeofday-64.o.d -nostdinc -I./arch/powerpc/include -I./arch/powerpc/include/generated  -I./include -I./arch/powerpc/include/uapi -I./arch/powerpc/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h -D__KERNEL__ -I ./arch/powerpc -DHAVE_AS_ATHIGH=1 -fmacro-prefix-map=./= -D__ASSEMBLY__ -fno-PIE -m64 -Wl,-a64 -mabi=elfv1 -mcpu=e500mc64 -mabi=elfv1 -mbig-endian    -Wl,-soname=linux-vdso64.so.1 -D__VDSO64__ -s -c -o arch/powerpc/kernel/vdso/gettimeofday-64.o arch/powerpc/kernel/vdso/gettimeofday.S

Reported-by: Jan-Benedict Glaw <jbglaw@lug-owl.de>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Pali Rohár <pali@kernel.org>
[mpe: Retain -Wa,-mpower4 -Wa,-many for Book3S 64 builds for now]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/758ad54128fa9dd2fdedc4c511592111cbded900.1671475543.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index d30a0941b0f811258bf4d48b22e0abb061b1324f..894d48cd049204de5cd1deb4b1fabff4f1d881bf 100644 (file)
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -201,10 +201,7 @@ KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
 # often slow when they are implemented at all
 KBUILD_CFLAGS          += $(call cc-option,-mno-string)
 
-cpu-as-$(CONFIG_40x)           += -Wa,-m405
-cpu-as-$(CONFIG_44x)           += -Wa,-m440
 cpu-as-$(CONFIG_ALTIVEC)       += $(call as-option,-Wa$(comma)-maltivec)
-cpu-as-$(CONFIG_PPC_E500)              += -Wa,-me500
 
 # When using '-many -mpower4' gas will first try and find a matching power4
 # mnemonic and failing that it will allow any valid mnemonic that GAS knows
@@ -212,7 +209,6 @@ cpu-as-$(CONFIG_PPC_E500)           += -Wa,-me500
 # LLVM IAS doesn't understand either flag: https://github.com/ClangBuiltLinux/linux/issues/675
 # but LLVM IAS only supports ISA >= 2.06 for Book3S 64 anyway...
 cpu-as-$(CONFIG_PPC_BOOK3S_64) += $(call as-option,-Wa$(comma)-mpower4) $(call as-option,-Wa$(comma)-many)
-cpu-as-$(CONFIG_PPC_E500MC)    += $(call as-option,-Wa$(comma)-me500mc)
 
 KBUILD_AFLAGS += $(cpu-as-y)
 KBUILD_CFLAGS += $(cpu-as-y)