Re: arch/arm64/include/asm/atomic_ll_sc.h:298:9: error: unknown type name 'u128'

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

On Fri, Feb 23, 2024, at 10:10, Naresh Kamboju wrote:
> In file included from arch/arm64/include/asm/lse.h:5,
>                  from arch/arm64/include/asm/cmpxchg.h:14,
>                  from arch/arm64/include/asm/atomic.h:16,
>                  from include/linux/atomic.h:7,
>                  from include/asm-generic/bitops/atomic.h:5,
>                  from arch/arm64/include/asm/bitops.h:25,
>                  from include/linux/bitops.h:68,
>                  from arch/arm64/include/asm/memory.h:209,
>                  from arch/arm64/include/asm/page.h:46,
>                  from include/vdso/datapage.h:22,
>                  from lib/vdso/gettimeofday.c:5,
>
>                  from <command-line>:
> arch/arm64/include/asm/atomic_ll_sc.h:298:9: error: unknown type name 'u128'
>   298 |         u128 full;
>       |         ^~~~
> arch/arm64/include/asm/atomic_ll_sc.h:305:24: error: unknown type name 'u128'
>   305 | static __always_inline u128

The problem here is the separation of vdso/*.h headers and
linux/*.h headers.

Commit a0d2fcd62ac2 ("vdso/ARM: Make union vdso_data_store
available for all architectures") introduced a reference to
the asm/page.h in include/vdso/datapage.h, but this is outside
of the vdso/*.h namespace and doesn't work in the compat vdso.

I think it is only needed because of the PAGE_SIZE macro,
so that constant needs to come from somewhere else.

I have an older patch that I never merged to unify the
page size configuration in Kconfig, and could try to
dig that out if nobody has a better idea. If we do that,
we could introduce a CONFIG_PAGE_SIZE.

    Arnd