Linux and multy domain PCIe.

Linux and multy domain PCIe.

[fpaolo63]

Hi guru,

I'm working on a multi socket intel xeon platform.

We have 2 sockets and each socket has a PCIe RootComplex, and we'd to 
implement hw with 2 separated PCIe tree.

Can Linux kernel handle the 2 RC assigning a PCIe domain each one?

Do we need special BIOS in order to configure correctly the 2 sockets, 
QDPI channel, MMIO and MMU?

Can some one point me to one example or documents?

thanks in advanced

Paolo

Re: Linux and multy domain PCIe.

[Bjorn Helgaas]

On Wed, Oct 31, 2012 at 4:02 AM, fpaolo63 <fpaolo63@gmail.com> wrote:
> Hi guru,
>
> I'm working on a multi socket intel xeon platform.
>
> We have 2 sockets and each socket has a PCIe RootComplex, and we'd to
> implement hw with 2 separated PCIe tree.
>
> Can Linux kernel handle the 2 RC assigning a PCIe domain each one?
>
> Do we need special BIOS in order to configure correctly the 2 sockets, QDPI
> channel, MMIO and MMU?
>
> Can some one point me to one example or documents?

Yes, Linux supports multiple PCI domains (also known as PCI segment groups).

On x86, the BIOS should provide a ACPI PNP0A08/PNP0A03 device for each
root complex.  See drivers/acpi/pci_root.c for details.

Fwd: Linux and multy domain PCIe.

[paolo faverio]

resend to list

---------- Forwarded message ----------
From: paolo faverio <fpaolo63@gmail.com>
Date: Wed, Oct 31, 2012 at 3:21 PM
Subject: Re: Linux and multy domain PCIe.
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org


Thanks Bjorn,
I'm going to dig on it.

one silly question
Enabling both the RC, do l have  255  pci bus ids for each PCI segment
group?

thanks
paolo


On Wed, Oct 31, 2012 at 1:23 PM, Bjorn Helgaas <bhelgaas@google.com> wrote:
>
> On Wed, Oct 31, 2012 at 4:02 AM, fpaolo63 <fpaolo63@gmail.com> wrote:
> > Hi guru,
> >
> > I'm working on a multi socket intel xeon platform.
> >
> > We have 2 sockets and each socket has a PCIe RootComplex, and we'd to
> > implement hw with 2 separated PCIe tree.
> >
> > Can Linux kernel handle the 2 RC assigning a PCIe domain each one?
> >
> > Do we need special BIOS in order to configure correctly the 2 sockets,
> > QDPI
> > channel, MMIO and MMU?
> >
> > Can some one point me to one example or documents?
>
> Yes, Linux supports multiple PCI domains (also known as PCI segment
> groups).
>
> On x86, the BIOS should provide a ACPI PNP0A08/PNP0A03 device for each
> root complex.  See drivers/acpi/pci_root.c for details.

Re: Linux and multy domain PCIe.

[Bjorn Helgaas]

On Wed, Oct 31, 2012 at 8:21 AM, paolo faverio <fpaolo63@gmail.com> wrote:
> Thanks Bjorn,
> I'm going to dig on it.
>
> one silly question
> Enabling both the RC, do l have  255  pci bus ids for each PCI segment
> group?

Yes.  256, actually (0x00-0xff).

> On Wed, Oct 31, 2012 at 1:23 PM, Bjorn Helgaas <bhelgaas@google.com> wrote:
>>
>> On Wed, Oct 31, 2012 at 4:02 AM, fpaolo63 <fpaolo63@gmail.com> wrote:
>> > Hi guru,
>> >
>> > I'm working on a multi socket intel xeon platform.
>> >
>> > We have 2 sockets and each socket has a PCIe RootComplex, and we'd to
>> > implement hw with 2 separated PCIe tree.
>> >
>> > Can Linux kernel handle the 2 RC assigning a PCIe domain each one?
>> >
>> > Do we need special BIOS in order to configure correctly the 2 sockets,
>> > QDPI
>> > channel, MMIO and MMU?
>> >
>> > Can some one point me to one example or documents?
>>
>> Yes, Linux supports multiple PCI domains (also known as PCI segment
>> groups).
>>
>> On x86, the BIOS should provide a ACPI PNP0A08/PNP0A03 device for each
>> root complex.  See drivers/acpi/pci_root.c for details.
>
>