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

[Christophe Leroy]

Le 08/08/2022 à 13:48, Sathvika Vasireddy a écrit :
> Since we need an alignment of 4 bytes, override
> __ALIGN() and __ALIGN_STR() accordingly.

Why/When do we now need an alignment of 4 bytes ? Please explain the 
reason in the commit message.

> 
> 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)

Why do you need to use __stringify ?

ARM64 does:

#define __ALIGN		.align 2
#define __ALIGN_STR	".align 2"




> +
>   #ifdef CONFIG_PPC64_ELF_ABI_V1
>   #define cond_syscall(x) \
>   	asm ("\t.weak " #x "\n\t.set " #x ", sys_ni_syscall\n"		\