Re: [PATCH v2 02/16] powerpc: override __ALIGN() and __ALIGN_STR() macros

[Sathvika Vasireddy]

Hi Christophe,

On 29/08/22 18:56, Christophe Leroy wrote:
> Le 29/08/2022 à 07:52, Sathvika Vasireddy a écrit :
> > Powerpc instructions must be word-aligned. Currently,
> > there is an alignment of 16 bytes (by default), and it is
> > much more than what is required for powerpc (4 bytes).
> >
> > The default expansion of __ALIGN() macro is:
> > #define __ALIGN       .align 4,0x90
> >
> > Since Powerpc Linux does not require a 16 byte alignment,
> > override __ALIGN() and __ALIGN_STR() macros to use required
> > 4 byte alignment.
> >
> > Signed-off-by: Sathvika Vasireddy <sv@xxxxxxxxxxxxx>
> > ---
> >    arch/powerpc/include/asm/linkage.h | 4 ++++
> >    1 file changed, 4 insertions(+)
> >
> > diff --git a/arch/powerpc/include/asm/linkage.h b/arch/powerpc/include/asm/linkage.h
> > index b71b9582e754..8df88fe61438 100644
> > --- a/arch/powerpc/include/asm/linkage.h
> > +++ b/arch/powerpc/include/asm/linkage.h
> > @@ -2,8 +2,12 @@
> >    #ifndef _ASM_POWERPC_LINKAGE_H
> >    #define _ASM_POWERPC_LINKAGE_H
> >    
> > +#include <linux/stringify.h>
> >    #include <asm/types.h>
> >    
> > +#define __ALIGN			.align 2
> > +#define __ALIGN_STR		__stringify(__ALIGN)
> > +
> I still can't see the added value of using __stringify() macro here. In
> order to use that macro you have to include linux/stringify.h . Usually
> we try to minimise the amount of headers required by other headers.
Oh ok, makes sense to me. I'll wait for a day to see if there are any
other comments, and make this change as part of v3.

Thanks for reviewing!

- Sathvika