Re: [PATCH 5/6] MIPS: implement architecture dependent 'pci_remap_iospace()'

[Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx>]

Hi Arnd,

On Sat, Sep 25, 2021 at 7:32 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Fri, Sep 24, 2021 at 11:11 PM Sergio Paracuellos
> <sergio.paracuellos@xxxxxxxxx> wrote:
> >
> > To make PCI IO work we need to properly virtually map IO cpu physical address
> > and set this virtual address as the address of the first PCI IO port which
> > is set using function 'set_io_port_base()'.
> >
> > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx>
>
> Acked-by: Arnd Bergmann <arnd@xxxxxxxx>

Thanks!

>
> > +int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
> > +{
> > +       size_t size = (res->end - res->start) + 1;
> > +       unsigned long vaddr = (unsigned long)ioremap(phys_addr, size);
> > +
> > +       set_io_port_base(vaddr);
> > +       return 0;
> > +}
>
> It might be good to check that res->start is zero here, otherwise
> the io_port_base would be off. That could happen if you ever have more
> than one bridge.

Do you mean something like the following?

int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
{
    unsigned long vaddr;
    size_t size;

    if (res->start != 0) {
         // Should I WARN_ONCE or just show an error/warning message??
         WARN_ONCE(1, "resource start must be zero\n");
         return -ENODEV;
   }

     size = (res->end - res->start) + 1;
     vaddr = (unsigned long)ioremap(phys_addr, size);
     return 0;
}

Thanks,
    Sergio Paracuellos
>
>         Arnd