Re: [PATCH v8 01/14] Consolidate IO memcpy/memset into iomap_copy.c

["Arnd Bergmann" <arnd@arndb.de>]

On Tue, Oct 8, 2024, at 07:50, Julian Vetter wrote:
> diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
> index 80de699bf6af..f14655ed4d9d 100644
> --- a/include/asm-generic/io.h
> +++ b/include/asm-generic/io.h
> @@ -102,6 +102,12 @@ static inline void log_post_read_mmio(u64 val, u8 
> width, const volatile void __i
> 
>  #endif /* CONFIG_TRACE_MMIO_ACCESS */
> 
> +extern void memcpy_fromio(void *to, const volatile void __iomem *from,
> +			  size_t count);
> +extern void memcpy_toio(volatile void __iomem *to, const void *from,
> +			size_t count);
> +extern void memset_io(volatile void __iomem *dst, int c, size_t count);
> +

I think having this globally visible is the reason you are running
into the mismatched prototypes. The patches to change the architecture
specific implementations are all good, but I would instead add
#ifdef checks around the prototypes the same way you do for the
implementation, to make the series bisectible and shorter.

 include/asm-generic/io.h |  58 ++----------------
 lib/iomap_copy.c         | 127 +++++++++++++++++++++++++++++++++++++++

Along the same lines, I would change lib/Makefile to build
this file unconditionally even on architectures that don't
set CONFIG_HAS_IOMEM. Again, strengthening the driver dependencies
is good, but it feels like a distraction here when we just need the
common implementation to be available.

       Arnd