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From: Kumar Gala <galak@kernel.crashing.org>
Subject: Re: [PATCH] force -mno-string option on cell
Date: Fri, 23 Mar 2007 08:37:16 -0500
To: Akinobu Mita <mita@fixstars.com>
Cc: Arnd Bergmann <arnd@arndb.de>, Paul Mackerras <paulus@samba.org>,
	cbe-oss-dev@ozlabs.org, linuxppc-dev list <linuxppc-dev@ozlabs.org>
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On Mar 23, 2007, at 7:06 AM, Akinobu Mita wrote:

> GCC may generate inline copy loop to handle memcpy() function
> instead of kernel defined memcpy() with -mstring or -Os.
> But this inlined version of memcpy() caused an alignment interrupt
> when copying from SPU local store on PS3.
> (http://ozlabs.org/pipermail/cbe-oss-dev/2007-March/001348.html)
>
> This patch deletes -mstring option on all powerpc and force -mno- 
> string
> option on Cell.
>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Paul Mackerras <paulus@samba.org>
> Signed-off-by: Akinobu Mita <mita@fixstars.com>

Nack.  If GCC is now putting string instructions even if you don't  
specify -mstring than we also need this for CONFIG_FSL_BOOKE.  Please  
fix that up as well.

- k

> ---
>  arch/powerpc/Makefile |    5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> Index: 2.6-git-ps3/arch/powerpc/Makefile
> ===================================================================
> --- 2.6-git-ps3.orig/arch/powerpc/Makefile
> +++ 2.6-git-ps3/arch/powerpc/Makefile
> @@ -102,8 +102,9 @@ CFLAGS += $(call cc-option,-mno-altivec)
>  # kernel considerably.
>  CFLAGS += $(call cc-option,-funit-at-a-time)
>
> -ifndef CONFIG_FSL_BOOKE
> -CFLAGS		+= -mstring
> +# No string instruction for SPE local store areas
> +ifeq ($(CONFIG_PPC_CELL),y)
> +CFLAGS		+= -mno-string
>  endif
>
>  ifeq ($(CONFIG_6xx),y)
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