kernel_optimize_test/arch/mips/loongson64/Platform
Aurelien Jarno 3896c324bb MIPS: Support binutils configured with --enable-mips-fix-loongson3-llsc=yes
commit 5373ae67c3aad1ab306cc722b5a80b831eb4d4d1 upstream.

From version 2.35, binutils can be configured with
--enable-mips-fix-loongson3-llsc=yes, which means it defaults to
-mfix-loongson3-llsc. This breaks labels which might then point at the
wrong instruction.

The workaround to explicitly pass -mno-fix-loongson3-llsc has been
added in Linux version 5.1, but is only enabled when building a Loongson
64 kernel. As vendors might use a common toolchain for building Loongson
and non-Loongson kernels, just move that workaround to
arch/mips/Makefile. At the same time update the comments to reflect the
current status.

Cc: stable@vger.kernel.org # 5.1+
Cc: YunQiang Su <syq@debian.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:25 +01:00

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#
# Loongson Processors' Support
#
cflags-$(CONFIG_CPU_LOONGSON64) += -Wa,--trap
#
# binutils from v2.25 on and gcc starting from v4.9.0 treat -march=loongson3a
# as MIPS64 R2; older versions as just R1. This leaves the possibility open
# that GCC might generate R2 code for -march=loongson3a which then is rejected
# by GAS. The cc-option can't probe for this behaviour so -march=loongson3a
# can't easily be used safely within the kbuild framework.
#
ifeq ($(call cc-ifversion, -ge, 0409, y), y)
ifeq ($(call ld-ifversion, -ge, 225000000, y), y)
cflags-$(CONFIG_CPU_LOONGSON64) += \
$(call cc-option,-march=loongson3a -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
else
cflags-$(CONFIG_CPU_LOONGSON64) += \
$(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
endif
else
cflags-$(CONFIG_CPU_LOONGSON64) += \
$(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 += $(call cc-option,-mno-loongson-mmi)
#
# Loongson Machines' Support
#
cflags-$(CONFIG_MACH_LOONGSON64) += -I$(srctree)/arch/mips/include/asm/mach-loongson64 -mno-branch-likely
load-$(CONFIG_CPU_LOONGSON64) += 0xffffffff80200000