Re: [PATCH v4 10/37] sh: Common PCI framework support

On Tue, Nov 14, 2023, at 03:00, Yoshinori Sato wrote:
> When CONFIG_OF=y, a common PCI framework is used.
> The new driver also needs to reference PCI headers, so move the
> necessary header files to a public location rather than a private one.
>
> Signed-off-by: Yoshinori Sato <[email protected]>
> ---
>  arch/sh/include/asm/io.h                      | 40 +++++++++++++------
>  .../sh/{drivers/pci => include/asm}/pci-sh4.h |  7 ++--
>  .../{drivers/pci => include/asm}/pci-sh7751.h |  0
>  .../{drivers/pci => include/asm}/pci-sh7780.h |  0
>  arch/sh/include/asm/pci.h                     |  4 ++

I think ideally the PCI host driver should be moved to
drivers/pci/controller, but I'm not sure if that solves
your problem here. There should normally be no need to
put driver specific headers into a global location.
 
>  #define IO_SPACE_LIMIT 0xffffffff

The IO_SPACE_LIMIT is wrong here, as most of the address space
is not actually reserved for port I/O. Usually you want just
64KB here, but you can also make this PIO_MASK I think.

> +#ifdef __KERNEL__
> +#define PCI_IOBASE	((void __iomem *)0xfe240000UL)
> +
> +#define HAVE_ARCH_PIO_SIZE
> +#define PIO_OFFSET	0xfe240000UL
> +#define PIO_MASK	0x3ffffUL
> +#define PIO_RESERVED	0x40000UL
> +#endif /* __KERNEL__ */

As far as I understand the generic iomap code, this does
not work because PIO_OFFSET has to be smaller than
PIO_RESERVED. Once you remove the GENERIC_IOMAP hack, it
should no longer matter.

      Arnd