path: root/arch
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authorPaul Burton <paul.burton@mips.com>2019-10-10 18:54:03 +0000
committerPaul Burton <paul.burton@mips.com>2019-10-10 11:58:52 -0700
commit2f2b4fd674cadd8c6b40eb629e140a14db4068fd (patch)
treee023cae4f998b44251f058415364b0b1ff890c0f /arch
parent38dffe1e4dde1d3174fdce09d67370412843ebb5 (diff)
MIPS: Disable Loongson MMI instructions for kernel build
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
Diffstat (limited to 'arch')
2 files changed, 5 insertions, 0 deletions
diff --git a/arch/mips/loongson64/Platform b/arch/mips/loongson64/Platform
index c1a4d4dc4665..9f79908f5063 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)
+# 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)) \

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