Re: [PATCH v2 1/4] pci: OF: Fix the conversion of IO ranges into IO resources.

From: Liviu Dudau
Date: Thu Feb 27 2014 - 14:14:22 EST


On Thu, Feb 27, 2014 at 11:19:51AM -0700, Jason Gunthorpe wrote:
> On Thu, Feb 27, 2014 at 01:06:39PM +0000, Liviu Dudau wrote:
> > + if (res->flags & IORESOURCE_IO) {
> > + unsigned long port;
> > + port = pci_address_to_pio(range->pci_addr);
>
> This looks very suspicious, pci_addr is not unique across all domains,
> so there is no way to convert from a pci_addr to the virtual IO
> address without knowing the domain number as well.
>
> I would like to see it be:
> port = pci_address_to_pio(range->cpu_addr);
>
> cpu_addr is unique across all domains.

Jason,

First thanks for reviewing the updated series.

We have agreed early on that indeed using range->cpu_addr is the correct aproach
and me taking the lazy shortcut of using range->pci_addr because of the broken
default implementation of pci_address_to_pio is wrong. I will fix this for v3.

The outstanding issue is how to fix pci_address_to_pio() as it will not
for for range->cpu_addr > IO_SPACE_LIMIT (16MB in my case).

Best regards,
Liviu

>
> Looking at the microblaze and PPC versions I think the above version
> is actually correct (assuming io_base_phys is the CPU address of the
> IO window)
>
> Jason
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