| From | Geert Uytterhoeven <> | Date | Tue, 28 Dec 2021 11:08:05 +0100 | Subject | Re: [RFC 02/32] Kconfig: introduce HAS_IOPORT option and select it as necessary |
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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...
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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