From a8140f36af2a8b63fd507bd8c1fa00df7819e0de Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Thu, 19 Feb 2015 13:47:20 +0100 Subject: [PATCH] MIPS: Makefile: Pass -march option on Loongson3A cores The loongson 3A cores do not select a suitable -march option so the build system uses the default one from the toolchain. This may or may not be suitable for a loongson 3A build. In order to avoid that, we explicitly set a suitable -march option for that core. Furthermore, some very old compilers don't support -march= at all and there is the possibility of toolchain combinations such as GCC 4.9 and binutils 2.24 for which -march=loongson3a will result in MIPS64 R2 code being generated but then rejected by GAS. So treat the Longsoon 3A as an R2 CPU. Signed-off-by: Ralf Baechle --- arch/mips/Makefile | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/mips/Makefile b/arch/mips/Makefile index 2563a088d3b8..4547719e4e61 100644 --- a/arch/mips/Makefile +++ b/arch/mips/Makefile @@ -182,6 +182,16 @@ cflags-$(CONFIG_CPU_CAVIUM_OCTEON) += -Wa,-march=octeon endif cflags-$(CONFIG_CAVIUM_CN63XXP1) += -Wa,-mfix-cn63xxp1 cflags-$(CONFIG_CPU_BMIPS) += -march=mips32 -Wa,-mips32 -Wa,--trap +# +# binutils from v2.25 on and gcc starting from v4.9.0 treat -march=loongson3a +# as MIPS64 R1; older versions as just R1. This leaves the possibility open +# that GCC might generate R2 code for -march=loongson3a which then is rejected +# by GAS. The cc-option can't probe for this behaviour so -march=loongson3a +# can't easily be used safely within the kbuild framework. +# +cflags-$(CONFIG_CPU_LOONGSON3) += \ + $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64) \ + -Wa,-mips64r2 -Wa,--trap cflags-$(CONFIG_CPU_R4000_WORKAROUNDS) += $(call cc-option,-mfix-r4000,) cflags-$(CONFIG_CPU_R4400_WORKAROUNDS) += $(call cc-option,-mfix-r4400,)