GCC 9.x automatically enables support for Loongson MMI instructions when using some -march= flags, and then errors out when -msoft-float is specified with:

cc1: error: ‘-mloongson-mmi’ must be used with ‘-mhard-float’

The kernel shouldn't be using these MMI instructions anyway, just as it doesn't use floating point instructions. Explicitly disable them in order to fix the build with GCC 9.x.

Signed-off-by: Paul Burton paul.burton@mips.com Fixes: 3702bba5eb4f ("MIPS: Loongson: Add GCC 4.4 support for Loongson2E") Fixes: 6f7a251a259e ("MIPS: Loongson: Add basic Loongson 2F support") Fixes: 5188129b8c9f ("MIPS: Loongson-3: Improve -march option and move it to Platform") Cc: Huacai Chen chenhc@lemote.com Cc: Jiaxun Yang jiaxun.yang@flygoat.com Cc: stable@vger.kernel.org # v2.6.32+ ---

arch/mips/loongson64/Platform | 4 ++++ arch/mips/vdso/Makefile | 1 + 2 files changed, 5 insertions(+)

diff --git a/arch/mips/loongson64/Platform b/arch/mips/loongson64/Platform index 28172500f95a..2855daf92fe8 100644 --- a/arch/mips/loongson64/Platform +++ b/arch/mips/loongson64/Platform @@ -66,6 +66,10 @@ else $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64) endif

+# Some -march= flags enable MMI instructions, and GCC complains about that +# support being enabled alongside -msoft-float. Thus explicitly disable MMI. +cflags-y += $(call cc-option,-mno-loongson-mmi) + # # Loongson Machines' Support # diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile index 807f0f782f75..996a934ece7d 100644 --- a/arch/mips/vdso/Makefile +++ b/arch/mips/vdso/Makefile @@ -15,6 +15,7 @@ ccflags-vdso := \ $(filter -mmicromips,$(KBUILD_CFLAGS)) \ $(filter -march=%,$(KBUILD_CFLAGS)) \ $(filter -m%-float,$(KBUILD_CFLAGS)) \ + $(filter -mno-loongson-%,$(KBUILD_CFLAGS)) \ -D__VDSO__

ifdef CONFIG_CC_IS_CLANG