Subject: Re: [PATCH 3/4] powerpc: Add 64-bit CPU targets for gcc

From: Benjamin Herrenschmidt <[email-masked]>
Date: Mon, 30 Apr 2012 15:57:34 +1000

On Wed, 2012-04-18 at 09:33 -0500, Kumar Gala wrote:
> On Apr 17, 2012, at 11:45 PM, Anton Blanchard wrote:
> 
> > 
> > Add a menu to select various 64-bit CPU targets for gcc. We
> > default to -mtune=power7 and if gcc doesn't understand that we
> > fallback to -mtune=power4.
> > 
> > Signed-off-by: Anton Blanchard <[email-masked]>
> > ---
> 
> Can you add a target for e5500 cpu.

I'm going to put Anton patch in, can you send an add-on for e5500 ?

Cheers,
Ben.

> - k
> 
> > 
> > Index: linux-build/arch/powerpc/Makefile
> > ===================================================================
> > --- linux-build.orig/arch/powerpc/Makefile	2012-04-18 14:31:31.614666419 +1000
> > +++ linux-build/arch/powerpc/Makefile	2012-04-18 14:37:08.680708678 +1000
> > @@ -69,6 +69,16 @@ LDFLAGS_vmlinux	:= $(LDFLAGS_vmlinux-y)
> > 
> > CFLAGS-$(CONFIG_PPC64)	:= -mminimal-toc -mtraceback=no -mcall-aixdesc
> > CFLAGS-$(CONFIG_PPC32)	:= -ffixed-r2 -mmultiple
> > +
> > +CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power7,-mtune=power4)
> > +CFLAGS-$(CONFIG_CELL_CPU) += $(call cc-option,-mcpu=cell)
> > +CFLAGS-$(CONFIG_POWER4_CPU) += $(call cc-option,-mcpu=power4)
> > +CFLAGS-$(CONFIG_POWER5_CPU) += $(call cc-option,-mcpu=power5)
> > +CFLAGS-$(CONFIG_POWER6_CPU) += $(call cc-option,-mcpu=power6)
> > +CFLAGS-$(CONFIG_POWER7_CPU) += $(call cc-option,-mcpu=power7)
> > +
> > +CFLAGS-$(CONFIG_TUNE_CELL) += $(call cc-option,-mtune=cell)
> > +
> > KBUILD_CPPFLAGS	+= -Iarch/$(ARCH)
> > KBUILD_AFLAGS	+= -Iarch/$(ARCH)
> > KBUILD_CFLAGS	+= -msoft-float -pipe -Iarch/$(ARCH) $(CFLAGS-y)
> > @@ -76,22 +86,11 @@ CPP		= $(CC) -E $(KBUILD_CFLAGS)
> > 
> > CHECKFLAGS	+= -m$(CONFIG_WORD_SIZE) -D__powerpc__ -D__powerpc$(CONFIG_WORD_SIZE)__
> > 
> > -ifeq ($(CONFIG_PPC64),y)
> > -ifeq ($(CONFIG_POWER4_ONLY),y)
> > -	KBUILD_CFLAGS += $(call cc-option,-mcpu=power4)
> > -else
> > -	KBUILD_CFLAGS += $(call cc-option,-mtune=power4)
> > -endif
> > -endif
> > -
> > KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
> > 
> > -ifeq ($(CONFIG_TUNE_CELL),y)
> > -	KBUILD_CFLAGS += $(call cc-option,-mtune=cell)
> > -endif
> > -
> > -# No AltiVec instruction when building kernel
> > +# No AltiVec or VSX instructions when building kernel
> > KBUILD_CFLAGS += $(call cc-option,-mno-altivec)
> > +KBUILD_CFLAGS += $(call cc-option,-mno-vsx)
> > 
> > # No SPE instruction when building kernel
> > # (We use all available options to help semi-broken compilers)
> > Index: linux-build/arch/powerpc/platforms/Kconfig.cputype
> > ===================================================================
> > --- linux-build.orig/arch/powerpc/platforms/Kconfig.cputype	2012-04-18 14:31:25.134549903 +1000
> > +++ linux-build/arch/powerpc/platforms/Kconfig.cputype	2012-04-18 14:36:40.576207829 +1000
> > @@ -78,6 +78,36 @@ config PPC_BOOK3E_64
> > 
> > endchoice
> > 
> > +choice
> > +	prompt "CPU selection"
> > +	depends on PPC64
> > +	default GENERIC_CPU
> > +	help
> > +	  This will create a kernel which is optimised for a particular CPU.
> > +	  The resulting kernel may not run on other CPUs, so use this with care.
> > +
> > +	  If unsure, select Generic.
> > +
> > +config GENERIC_CPU
> > +	bool "Generic"
> > +
> > +config CELL_CPU
> > +	bool "Cell Broadband Engine"
> > +
> > +config POWER4_CPU
> > +	bool "POWER4"
> > +
> > +config POWER5_CPU
> > +	bool "POWER5"
> > +
> > +config POWER6_CPU
> > +	bool "POWER6"
> > +
> > +config POWER7_CPU
> > +	bool "POWER7"
> > +
> > +endchoice
> > +
> > config PPC_BOOK3S
> > 	def_bool y
> > 	depends on PPC_BOOK3S_32 || PPC_BOOK3S_64
> > _______________________________________________
> > Linuxppc-dev mailing list
> > [email-masked]
> > https://lists.ozlabs.org/listinfo/linuxppc-dev