On Fri, Dec 1, 2023, at 13:16, Philipp Stanner wrote:
>
> Arnd has suggested that architectures defining a custom inb() need their
> own iomem_is_ioport(), as well. I've grepped for inb() and found the
> following list of archs that define their own:
> - alpha
> - arm
> - m68k <--
> - parisc
> - powerpc
> - sh
> - sparc
> - x86 <--
>
> All of those have their own definitons of pci_iounmap(). Therefore, they
> don't need our generic version in the first place and, thus, also need
> no iomem_is_ioport().
What I meant of course is that they should define iomem_is_ioport()
in order to drop the custom pci_iounmap() and have only one remaining
definition of that function left.
The one special case that I missed the last time is s390, which
does not use GENERIC_PCI_IOMAP and will just require a separate
copy of pci_iounmap() to go along with the is custom pci_iomap().
> The two exceptions are x86 and m68k. The former uses lib/iomap.c through
> CONFIG_GENERIC_IOMAP, as Arnd pointed out in the previous discussion
> (thus, CONFIG_GENERIC_IOMAP is not really generic in this regard).
>
> So as I see it, only m68k WOULD need its own custom definition of
> iomem_is_ioport(). But as I understand it it doesn't because it uses the
> one from asm-generic/pci_iomap.h ??
At the moment, m68k gets the pci_iounmap() from lib/iomap.c
if PCI is enabled for coldfire, but that incorrectly calls
iounmap() on PCI_IO_PA if it gets passed a PIO address.
The version from asm-generic/io.h should fix this.
For classic m68k, there is no PCI, so nothing calls pci_iounmap().
> I wasn't entirely sure how to deal with the address ranges for the
> generic implementation in asm-generic/io.h. It's marked with a TODO.
> Input appreciated.
I commented on the function directly. To clarify, I think we should
be able to directly turn each pci_iounmap() definition into
a iomem_is_ioport() definition by keeping the logic unchanged
and just return 'true' for the PIO variant or 'false' for the MMIO
version.
> I removed the guard around define pci_iounmap in asm-generic/io.h. An
> alternative would be to have it be guarded by CONFIG_GENERIC_IOMAP and
> CONFIG_GENERIC_PCI_IOMAP, both. Without such a guard, there is no
> collision however, because generic pci_iounmap() from
> drivers/pci/iomap.c will only get pulled in when
> CONFIG_GENERIC_PCI_IOMAP is actually set.
The "#define pci_iomap" can be removed entirely I think.
Arnd
