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authorPaul Burton <paul.burton@mips.com>2019-10-10 18:54:03 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-10-17 13:45:31 -0700
commitaaa81d9e6523b4fe55aee536ce10bcc1c55b5d0f (patch)
treeb7eb5ec6b809c87d228d8cb2f8203ae91c918f7d
parente9360f393d7b188e8e80520c80886ebf28f9920d (diff)
downloadlinux-stable-rc-aaa81d9e6523b4fe55aee536ce10bcc1c55b5d0f.tar.gz
MIPS: Disable Loongson MMI instructions for kernel build
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 <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+ Cc: linux-mips@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/mips/loongson64/Platform4
-rw-r--r--arch/mips/vdso/Makefile1
2 files changed, 5 insertions, 0 deletions
diff --git a/arch/mips/loongson64/Platform b/arch/mips/loongson64/Platform
index 0fce4608aa886..12abf14aed4a3 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 6f10312e0c76c..c99fa1c1bd9cc 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)