This is a note to let you know that I've just added the patch titled
MIPS: Loongson2ef: Disable Loongson MMI instructions
to the 5.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mips-loongson2ef-disable-loongson-mmi-instructions.patch
and it can be found in the queue-5.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b13812ddea615b6507beef24f76540c0c1143c5c Mon Sep 17 00:00:00 2001
From: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
Date: Wed, 23 Sep 2020 18:33:12 +0800
Subject: MIPS: Loongson2ef: Disable Loongson MMI instructions
From: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
commit b13812ddea615b6507beef24f76540c0c1143c5c upstream.
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+
Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/mips/loongson2ef/Platform | 4 ++++
1 file changed, 4 insertions(+)
--- a/arch/mips/loongson2ef/Platform
+++ b/arch/mips/loongson2ef/Platform
@@ -22,6 +22,10 @@ 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
#
Patches currently in stable-queue which might be from jiaxun.yang@xxxxxxxxxxx are
queue-5.8/mips-loongson2ef-disable-loongson-mmi-instructions.patch
