xref: /linux/arch/mips/loongson64/Platform (revision 71e2f4dd5a65bd8dbca0b77661e75eea471168f8)
1#
2# Loongson Processors' Support
3#
4
5
6cflags-$(CONFIG_CPU_LOONGSON64)	+= -Wa,--trap
7
8#
9# Some versions of binutils, not currently mainline as of 2019/02/04, support
10# an -mfix-loongson3-llsc flag which emits a sync prior to each ll instruction
11# to work around a CPU bug (see __SYNC_loongson3_war in asm/sync.h for a
12# description).
13#
14# We disable this in order to prevent the assembler meddling with the
15# instruction that labels refer to, ie. if we label an ll instruction:
16#
17# 1: ll v0, 0(a0)
18#
19# ...then with the assembler fix applied the label may actually point at a sync
20# instruction inserted by the assembler, and if we were using the label in an
21# exception table the table would no longer contain the address of the ll
22# instruction.
23#
24# Avoid this by explicitly disabling that assembler behaviour. If upstream
25# binutils does not merge support for the flag then we can revisit & remove
26# this later - for now it ensures vendor toolchains don't cause problems.
27#
28cflags-$(CONFIG_CPU_LOONGSON64)	+= $(call as-option,-Wa$(comma)-mno-fix-loongson3-llsc,)
29
30#
31# binutils from v2.25 on and gcc starting from v4.9.0 treat -march=loongson3a
32# as MIPS64 R2; older versions as just R1.  This leaves the possibility open
33# that GCC might generate R2 code for -march=loongson3a which then is rejected
34# by GAS.  The cc-option can't probe for this behaviour so -march=loongson3a
35# can't easily be used safely within the kbuild framework.
36#
37ifeq ($(call cc-ifversion, -ge, 0409, y), y)
38  ifeq ($(call ld-ifversion, -ge, 225000000, y), y)
39    cflags-$(CONFIG_CPU_LOONGSON64)  += \
40      $(call cc-option,-march=loongson3a -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
41  else
42    cflags-$(CONFIG_CPU_LOONGSON64)  += \
43      $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
44  endif
45else
46    cflags-$(CONFIG_CPU_LOONGSON64)  += \
47      $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
48endif
49
50#
51# Loongson Machines' Support
52#
53
54platform-$(CONFIG_MACH_LOONGSON64) += loongson64/
55cflags-$(CONFIG_MACH_LOONGSON64) += -I$(srctree)/arch/mips/include/asm/mach-loongson64 -mno-branch-likely
56load-$(CONFIG_LOONGSON_MACH3X) += 0xffffffff80200000
57