From aaa81d9e6523b4fe55aee536ce10bcc1c55b5d0f Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Thu, 10 Oct 2019 18:54:03 +0000 Subject: [PATCH] MIPS: Disable Loongson MMI instructions for kernel build MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit 2f2b4fd674cadd8c6b40eb629e140a14db4068fd upstream. 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 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 Cc: Jiaxun Yang Cc: stable@vger.kernel.org # v2.6.32+ Cc: linux-mips@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- 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 0fce460..12abf14 100644 --- a/arch/mips/loongson64/Platform +++ b/arch/mips/loongson64/Platform @@ -43,6 +43,10 @@ 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 6f10312..c99fa1c 100644 --- a/arch/mips/vdso/Makefile +++ b/arch/mips/vdso/Makefile @@ -9,6 +9,7 @@ ccflags-vdso := \ $(filter -mmicromips,$(KBUILD_CFLAGS)) \ $(filter -march=%,$(KBUILD_CFLAGS)) \ $(filter -m%-float,$(KBUILD_CFLAGS)) \ + $(filter -mno-loongson-%,$(KBUILD_CFLAGS)) \ -D__VDSO__ ifeq ($(cc-name),clang) -- 2.7.4