2020-09-23 10:42:43

by Jiaxun Yang

Subject: [PATCH] MIPS: Loongson2ef: Disable Loongson MMI instructions

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 <[email protected]>
Fixes: 71e2f4dd5a65 ("MIPS: Fork loongson2ef from loongson64")
Reported-by: Thomas Bogendoerfer <[email protected]>
Cc: [email protected] # 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

2020-09-24 14:01:17

by Thomas Bogendoerfer

Subject: Re: [PATCH] MIPS: Loongson2ef: Disable Loongson MMI instructions

On Wed, Sep 23, 2020 at 06:33:12PM +0800, Jiaxun Yang wrote:
> 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 <[email protected]>
> Fixes: 71e2f4dd5a65 ("MIPS: Fork loongson2ef from loongson64")
> Reported-by: Thomas Bogendoerfer <[email protected]>
> Cc: [email protected] # v5.8+
> ---
> arch/mips/loongson2ef/Platform | 4 ++++
> 1 file changed, 4 insertions(+)

applied to mips-fixes.

Thomas.

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