Re: [RFC v2 01/39] Kconfig: introduce HAS_IOPORT option and select it as necessary

Maciej W. Rozycki
2022-05-01T22:40:47Z

On Fri, 29 Apr 2022, Niklas Schnelle wrote:

> We introduce a new HAS_IOPORT Kconfig option to indicate 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 such as s390 or
> where such support is optional. The "depends on" relations 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.
[...]
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index de3b32a507d2..4c55df08d6f1 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -47,6 +47,7 @@ config MIPS
> select GENERIC_SMP_IDLE_THREAD
> select GENERIC_TIME_VSYSCALL
> select GUP_GET_PTE_LOW_HIGH if CPU_MIPS32 && PHYS_ADDR_T_64BIT
> + select HAS_IOPORT
> select HAVE_ARCH_COMPILER_H
> select HAVE_ARCH_JUMP_LABEL
> select HAVE_ARCH_KGDB if MIPS_FP_SUPPORT

NAK, not all MIPS systems have the port I/O space, and we have it already
handled via the NO_IOPORT_MAP option. We'll need to have HAS_IOPORT set
to !NO_IOPORT_MAP (or vice versa) for the MIPS architecture.

Maciej