Re: x86: ppc fixes for find_first_bit

[Ingo Molnar <mingo@elte.hu>]

* Alexander van Heukelum <heukelum@fastmail.fm> wrote:

> Hello Thomas,
> 
> I see Ingo has applied three fixes to the x86-tree:
>     find_first_bit() ppc fix
>     powerpc: fix powerpc build
>     find_next_bit() fix
> 
> Could you please give some insight in what went wrong with
> ppc and powerpc?
> 
> "find_first_bit() ppc fix" disables the use of find_first_bit
> for every user of GENERIC_FIND_NEXT_BIT=y. It replaces it by a
> macro to call find_next_bit with offset=0. It should be possible
> for an arch to use GENERIC_FIND_NEXT_BIT=y and implement 
> find_first_bit by itself.
> 
> "powerpc: fix powerpc build" removes the private 'implementation'
> of asm-generic/bitops/find.h. It seems correct code to me. What
> was the problem here? If it is duplicate declarations, then
> I would suggest putting #ifndef GENERIC_FIND_NEXT_BIT around
> them.
> 
> "find_next_bit() fix" changes asm-generic/bitops/find.h to
> declare find_next_bit only if CONFIG_GENERIC_FIND_NEXT_BIT=n.
> That is indeed a good change. It would be better if this
> file disappeared completely, though.

we had trouble making ppc64 defconfig build fine with your bitops 
changes applied (Thomas might still have the build failure logs). The 
fixes are ad-hoc band-aids to get it to build. We used crosscompilers to 
build on ppc64.

	Ingo