Messages in this thread | | | Subject | Re: [RFC 02/32] Kconfig: introduce HAS_IOPORT option and select it as necessary | From | Michael Schmitz <> | Date | Wed, 29 Dec 2021 14:20:38 +1300 |
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Hi Geert, Niklas,
Am 28.12.2021 um 23:08 schrieb Geert Uytterhoeven: > Hi Niklas, > > On Mon, Dec 27, 2021 at 5:44 PM Niklas Schnelle <schnelle@linux.ibm.com> wrote: >> We introduce a new HAS_IOPORT Kconfig option to gate support for >> I/O port access. In a future patch HAS_IOPORT=n will disable compilation >> of the I/O accessor functions inb()/outb() and friends on architectures >> which can not meaningfully support legacy I/O spaces. On these platforms >> inb()/outb() etc are currently just stubs in asm-generic/io.h which when >> called will cause a NULL pointer access which some compilers actually >> detect and warn about. >> >> The dependencies on HAS_IOPORT in drivers as well as ifdefs for >> HAS_IOPORT specific sections will be added in subsequent patches on >> a per subsystem basis. Then a final patch will ifdef the I/O access >> functions on HAS_IOPORT thus turning any use not gated by HAS_IOPORT >> into a compile-time warning. >> >> Link: https://lore.kernel.org/lkml/CAHk-=wg80je=K7madF4e7WrRNp37e3qh6y10Svhdc7O8SZ_-8g@mail.gmail.com/ >> Co-developed-by: Arnd Bergmann <arnd@kernel.org> >> Signed-off-by: Arnd Bergmann <arnd@kernel.org> >> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> > > Thanks for your patch! > >> --- a/arch/m68k/Kconfig >> +++ b/arch/m68k/Kconfig >> @@ -16,6 +16,7 @@ config M68K >> select GENERIC_CPU_DEVICES >> select GENERIC_IOMAP >> select GENERIC_IRQ_SHOW >> + select HAS_IOPORT >> select HAVE_AOUT if MMU >> select HAVE_ASM_MODVERSIONS >> select HAVE_DEBUG_BUGVERBOSE > > This looks way too broad to me: most m68k platform do not have I/O > port access support. > > My gut feeling says: > > select HAS_IOPORT if PCI || ISA > > but that might miss some intricate details...
In particular, this misses the Atari ROM port ISA adapter case -
select HAS_IOPORT if PCI || ISA || ATARI_ROM_ISA
might do instead.
Cheers,
Michael
> > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds >
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