OpenCloudOS-Kernel/arch/mips/loongson2ef/Platform

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#
# Loongson Processors' Support
#
# Only gcc >= 4.4 have Loongson specific support
cflags-$(CONFIG_CPU_LOONGSON2EF) += -Wa,--trap
cflags-$(CONFIG_CPU_LOONGSON2E) += \
$(call cc-option,-march=loongson2e,-march=r4600)
cflags-$(CONFIG_CPU_LOONGSON2F) += \
$(call cc-option,-march=loongson2f,-march=r4600)
#
# Some versions of binutils, not currently mainline as of 2019/02/04, support
# an -mfix-loongson3-llsc flag which emits a sync prior to each ll instruction
# to work around a CPU bug (see __SYNC_loongson3_war in asm/sync.h for a
# description).
#
# We disable this in order to prevent the assembler meddling with the
# instruction that labels refer to, ie. if we label an ll instruction:
#
# 1: ll v0, 0(a0)
#
# ...then with the assembler fix applied the label may actually point at a sync
# instruction inserted by the assembler, and if we were using the label in an
# exception table the table would no longer contain the address of the ll
# instruction.
#
# Avoid this by explicitly disabling that assembler behaviour. If upstream
# binutils does not merge support for the flag then we can revisit & remove
# this later - for now it ensures vendor toolchains don't cause problems.
#
cflags-$(CONFIG_CPU_LOONGSON2EF) += $(call as-option,-Wa$(comma)-mno-fix-loongson3-llsc,)
# Enable the workarounds for Loongson2f
ifdef CONFIG_CPU_LOONGSON2F_WORKAROUNDS
ifeq ($(call as-option,-Wa$(comma)-mfix-loongson2f-nop,),)
$(error only binutils >= 2.20.2 have needed option -mfix-loongson2f-nop)
else
cflags-$(CONFIG_CPU_NOP_WORKAROUNDS) += -Wa$(comma)-mfix-loongson2f-nop
endif
ifeq ($(call as-option,-Wa$(comma)-mfix-loongson2f-jump,),)
$(error only binutils >= 2.20.2 have needed option -mfix-loongson2f-jump)
else
cflags-$(CONFIG_CPU_JUMP_WORKAROUNDS) += -Wa$(comma)-mfix-loongson2f-jump
endif
endif
#
# Loongson Machines' Support
#
cflags-$(CONFIG_MACH_LOONGSON2EF) += -I$(srctree)/arch/mips/include/asm/mach-loongson2ef -mno-branch-likely
load-$(CONFIG_LEMOTE_FULOONG2E) += 0xffffffff80100000
load-$(CONFIG_LEMOTE_MACH2F) += 0xffffffff80200000