[PATCH 2/2] ARM: kconfig: select HAVE_EFFICIENT_UNALIGNED_ACCESS for CPUv6+ && MMU

[Nicolas Pitre]

On Mon, 6 Jan 2014, Will Deacon wrote:

> Hi Nicolas,
> 
> On Tue, Dec 17, 2013 at 08:34:18PM +0000, Nicolas Pitre wrote:
> > On Tue, 17 Dec 2013, Will Deacon wrote:
> > 
> > > Modern ARM CPUs can perform efficient unaligned memory accesses in
> > > hardware and this feature is relied up on by code such as the dcache
> > > word-at-a-time name hashing.
> > > 
> > > This patch selects HAVE_EFFICIENT_UNALIGNED_ACCESS for these cores and
> > > reworks the kconfig select logic for DCACHE_WORD_ACCESS to use the new
> > > symbol.
> > > 
> > > Signed-off-by: Will Deacon <will.deacon at arm.com>
> > 
> > This symbol could be used in some more places too.  For example this 
> > would make the code a bit clearer:
> 
> Well spotted.
> 
> > diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
> > index 72abdc541f..12c3a5decc 100644
> > --- a/arch/arm/include/asm/uaccess.h
> > +++ b/arch/arm/include/asm/uaccess.h
> > @@ -19,7 +19,7 @@
> >  #include <asm/unified.h>
> >  #include <asm/compiler.h>
> >  
> > -#if __LINUX_ARM_ARCH__ < 6
> > +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
> >  #include <asm-generic/uaccess-unaligned.h>
> >  #else
> >  #define __get_user_unaligned __get_user
> 
> The original patch is now queued, so we can add this hunk as a follow-up
> cleanup patch. I've got you as the author, but can I add your S-o-B please?

Signed-off-by: Nicolas Pitre <nico at linaro.org>



> 
> Cheers,
> 
> Will
>