xref: /openbmc/linux/arch/mips/loongson64/Platform (revision fcbd8037)
1#
2# Loongson Processors' Support
3#
4
5# Only gcc >= 4.4 have Loongson specific support
6cflags-$(CONFIG_CPU_LOONGSON2)	+= -Wa,--trap
7cflags-$(CONFIG_CPU_LOONGSON2E) += \
8	$(call cc-option,-march=loongson2e,-march=r4600)
9cflags-$(CONFIG_CPU_LOONGSON2F) += \
10	$(call cc-option,-march=loongson2f,-march=r4600)
11# Enable the workarounds for Loongson2f
12ifdef CONFIG_CPU_LOONGSON2F_WORKAROUNDS
13  ifeq ($(call as-option,-Wa$(comma)-mfix-loongson2f-nop,),)
14    $(error only binutils >= 2.20.2 have needed option -mfix-loongson2f-nop)
15  else
16    cflags-$(CONFIG_CPU_NOP_WORKAROUNDS) += -Wa$(comma)-mfix-loongson2f-nop
17  endif
18  ifeq ($(call as-option,-Wa$(comma)-mfix-loongson2f-jump,),)
19    $(error only binutils >= 2.20.2 have needed option -mfix-loongson2f-jump)
20  else
21    cflags-$(CONFIG_CPU_JUMP_WORKAROUNDS) += -Wa$(comma)-mfix-loongson2f-jump
22  endif
23endif
24
25cflags-$(CONFIG_CPU_LOONGSON3)	+= -Wa,--trap
26
27#
28# Some versions of binutils, not currently mainline as of 2019/02/04, support
29# an -mfix-loongson3-llsc flag which emits a sync prior to each ll instruction
30# to work around a CPU bug (see loongson_llsc_mb() in asm/barrier.h for a
31# description).
32#
33# We disable this in order to prevent the assembler meddling with the
34# instruction that labels refer to, ie. if we label an ll instruction:
35#
36# 1: ll v0, 0(a0)
37#
38# ...then with the assembler fix applied the label may actually point at a sync
39# instruction inserted by the assembler, and if we were using the label in an
40# exception table the table would no longer contain the address of the ll
41# instruction.
42#
43# Avoid this by explicitly disabling that assembler behaviour. If upstream
44# binutils does not merge support for the flag then we can revisit & remove
45# this later - for now it ensures vendor toolchains don't cause problems.
46#
47cflags-$(CONFIG_CPU_LOONGSON3)	+= $(call as-option,-Wa$(comma)-mno-fix-loongson3-llsc,)
48
49#
50# binutils from v2.25 on and gcc starting from v4.9.0 treat -march=loongson3a
51# as MIPS64 R2; older versions as just R1.  This leaves the possibility open
52# that GCC might generate R2 code for -march=loongson3a which then is rejected
53# by GAS.  The cc-option can't probe for this behaviour so -march=loongson3a
54# can't easily be used safely within the kbuild framework.
55#
56ifeq ($(call cc-ifversion, -ge, 0409, y), y)
57  ifeq ($(call ld-ifversion, -ge, 225000000, y), y)
58    cflags-$(CONFIG_CPU_LOONGSON3)  += \
59      $(call cc-option,-march=loongson3a -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
60  else
61    cflags-$(CONFIG_CPU_LOONGSON3)  += \
62      $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
63  endif
64else
65    cflags-$(CONFIG_CPU_LOONGSON3)  += \
66      $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
67endif
68
69# Some -march= flags enable MMI instructions, and GCC complains about that
70# support being enabled alongside -msoft-float. Thus explicitly disable MMI.
71cflags-y += $(call cc-option,-mno-loongson-mmi)
72
73#
74# Loongson Machines' Support
75#
76
77platform-$(CONFIG_MACH_LOONGSON64) += loongson64/
78cflags-$(CONFIG_MACH_LOONGSON64) += -I$(srctree)/arch/mips/include/asm/mach-loongson64 -mno-branch-likely
79load-$(CONFIG_LEMOTE_FULOONG2E) += 0xffffffff80100000
80load-$(CONFIG_LEMOTE_MACH2F) += 0xffffffff80200000
81load-$(CONFIG_LOONGSON_MACH3X) += 0xffffffff80200000
82