Re: [PATCH RFC 1/2] m68k: io_mm.h: conditionalize ISA address translation on Atari

[Michael Schmitz <schmitzmic@gmail.com>]

Hi Geert,

Am 04.06.2021 um 19:54 schrieb Geert Uytterhoeven:
>>> I have to wonder whether there is a nice simple definition for MULTI_ISA.
>>
>> As I understand it, MULTI_ISA means that different byte orders and/or
>> different address translations need to be used in the same kernel, so
>> all that cannot be decided at build time.
>>
>> As long as there is only a single platform that will use this code (ISA
>> only used on a single platform, and neither Atari IDE nor EtherNEC
>> used), MULTI_ISA is not needed.
>>
>> If we have Kconfig symbols for 'single platform only', and
>> 'multi-platform ISA use', that might be shorter to write and easier to
>> understand. Geert?
>
> It would be nice to have that automatically, like with the current
> MULTI_ISA define (and all the MACH_* in arch/m68k/include/asm/setup.h).
> Perhaps we should extend kconfig syntax to define a group of
> related symbols, and to automatically generate CONFIG_FOO_MULTI or
> CONFIG_FOO_SINGLE (and even CONFIG_BAR_ONLY?) symbols?

I take it this is not supported by our current Kconfig syntax?

>
> group ISA
>      item ATARI_ROM_ISA
>      item AMIGA_PCMCIA
>      item Q40
>
> => CONFIG_ISA_MULTI or CONFIG_ISA_SINGLE (+ e.g. ATARI_ROM_ISA_ONLY
>    if appropriate).
>
> Are there other users who can benefit from this?

Nothing comes to mind immediately. But there will be other drivers 
shared between different architectures (Mac / PowerPC?) that might benefit.

Cheers,

	Michael


>
> Gr{oetje,eeting}s,
>
>                         Geert
>