Re: [PATCH v3 5/6] MIPS: implement architecture-specific 'pci_remap_iospace()'

Arnd Bergmann
2021-12-16T12:55:26Z

On Thu, Dec 16, 2021 at 12:44 PM Xi Ruoyao <xry111@mengyan1223.wang> wrote:
>
> On Sat, 2021-09-25 at 22:32 +0200, Sergio Paracuellos 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()'.
> >
> > Acked-by: Arnd Bergmann <arnd@arndb.de>
> > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
>
> Hi,
>
> the change is causing a WARNING on loongson64g-4core-ls7a:
>
> [ 0.105781] loongson-pci 1a000000.pci: IO 0x0018020000..0x001803ffff ->
> 0x0000020000
> [ 0.105792] loongson-pci 1a000000.pci: MEM 0x0040000000..0x007fffffff ->
> 0x0040000000
> [ 0.105801] ------------[ cut here ]------------
> [ 0.105804] WARNING: CPU: 0 PID: 1 at arch/mips/pci/pci-generic.c:55 pci_remap_iospace+0x80/0x88
> [ 0.105815] resource start address is not zero
>
> I'm not sure how to fix this one.

It looks like this machine has two I/O spaces, one for ISA at 0x18000000/0x00000
and one for PCI at 0x18020000/0x20000, but the implementation assumes there
is only one. If you want to use pci_remap_iospace() on this platform,
it needs to
be extended to allow more than one such space.

Arnd