[PATCH] MIPS: Loongson2ef: Disable Loongson MMI instructions

[Jiaxun Yang]

It was missed when I was forking Loongson2ef from Loongson64 but
should be applied to Loongson2ef as march=loongson2f
will also enable Loongson MMI in GCC-9+.

Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
Fixes: 71e2f4dd5a65 ("MIPS: Fork loongson2ef from loongson64")
Reported-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.8+
---
 arch/mips/loongson2ef/Platform | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/mips/loongson2ef/Platform b/arch/mips/loongson2ef/Platform
index 4ab55f1123a0..ae023b9a1c51 100644
--- a/arch/mips/loongson2ef/Platform
+++ b/arch/mips/loongson2ef/Platform
@@ -44,6 +44,10 @@ ifdef CONFIG_CPU_LOONGSON2F_WORKAROUNDS
   endif
 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
 #
-- 
2.28.0