Re: [PATCH 17/25] s390: move the XOR code to lib/raid/

Heiko Carstens
2026-02-27T09:11:47Z

On Thu, Feb 26, 2026 at 07:10:29AM -0800, Christoph Hellwig wrote:
> Move the optimized XOR into lib/raid and include it it in xor.ko
> instead of unconditionally building it into the main kernel image.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> arch/s390/lib/Makefile | 2 +-
> lib/raid/xor/Makefile | 1 +
> {arch/s390/lib => lib/raid/xor/s390}/xor.c | 2 --
> 3 files changed, 2 insertions(+), 3 deletions(-)
> rename {arch/s390/lib => lib/raid/xor/s390}/xor.c (98%)

FWIW:
Acked-by: Heiko Carstens <hca@linux.ibm.com>

However, I just had a look at the s390 implementation and just saw that the
inline assembly constraints for xor_xc_2() are incorrect. "bytes", "p1",
and "p2" are input operands, while all three of them are modified within
the inline assembly. Given that the function consists only of this inline
assembly I doubt that this causes any harm, however I still want to fix
this now; but your patch should apply fine with or without this fixed.