[RFT] ARM: shmobile: rcar-gen2: Fix build breakage

[Krzysztof Kozlowski]

On nie, 2014-11-02 at 10:10 +0100, Geert Uytterhoeven wrote:
> On Fri, Oct 31, 2014 at 4:02 PM, Krzysztof Kozlowski
> <k.kozlowski at samsung.com> wrote:
> > Fix build breakage when building allmodconfig or allyesconfig introduced
> > by adding ISB instruction to rcar_gen2_timer_init() function
> > (9ce3fa6816c2 "ARM: shmobile: rcar-gen2: Add CA7 arch_timer
> > initialization for r8a7794"):
> >
> >   CC      arch/arm/mach-shmobile/setup-rcar-gen2.o
> > /tmp/cc770qt0.s: Assembler messages:
> > /tmp/cc770qt0.s:378: Error: selected processor does not support ARM mode `isb'
> > /tmp/cc770qt0.s:381: Error: selected processor does not support ARM mode `isb'
> > /tmp/cc770qt0.s:383: Error: selected processor does not support ARM mode `isb'
> > make[1]: *** [arch/arm/mach-shmobile/setup-rcar-gen2.o] Error 1
> >
> > Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>
> > ---
> >  arch/arm/mach-shmobile/setup-rcar-gen2.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm/mach-shmobile/setup-rcar-gen2.c b/arch/arm/mach-shmobile/setup-rcar-gen2.c
> > index 3dd6edd9bd1d..47f85643785f 100644
> > --- a/arch/arm/mach-shmobile/setup-rcar-gen2.c
> > +++ b/arch/arm/mach-shmobile/setup-rcar-gen2.c
> > @@ -68,6 +68,7 @@ void __init rcar_gen2_timer_init(void)
> >                  * secure code.
> >                  */
> >                 asm volatile(
> > +               "       .arch   armv7-a\n"
> >                 "       cps     0x16\n"
> >                 "       mrc     p15, 0, r1, c1, c1, 0\n"
> >                 "       orr     r0, r1, #1\n"
> 
> Shouldn't the ".arch" be reset to some generic value afterwards?

This is per compilation unit so this would make same effect as adding in
Makefile:
CFLAGS_setup-rcar-gen2.o := -march=armv7-a

In both cases the whole unit is affected by armv7-a. Setting it to armv6
won't always mean "reset" because shmobile config could be compiled by
default in armv7.

Best regards,
Krzysztof