Re: [PATCH V9 03/18] PCI: Add weak pcibios_iov_resource_size() interface

[Wei Yang <weiyang@linux.vnet.ibm.com>]

On Thu, Nov 20, 2014 at 07:51:40AM +1100, Benjamin Herrenschmidt wrote:
>On Wed, 2014-11-19 at 10:23 -0700, Bjorn Helgaas wrote:
>> 
>> Yes, I've read that many times.  What's missing is the connection between a
>> PE and the things in the PCI specs (buses, devices, functions, MMIO address
>> space, DMA, MSI, etc.)  Presumably the PE structure imposes constraints on
>> how the core uses the standard PCI elements, but we don't really have a
>> clear description of those constraints yet.
>
>Right, a "PE" is a HW concept in fact in our bridges, that essentially is
>a shared isolation state between DMA, MMIO, MSIs, PCIe error messages,...
>for a given "domain" or set of PCI functions.
>
>The techniques of how the HW resources are mapped to PE and associated
>constraints are slightly different from one generation of our chips to
>the next. In general, P7 follows an architecture known as "IODA" and P8
>"IODA2". I'm trying to get that spec made available via OpenPower but
>that hasn't happened yet.
>
>In this case we mostly care about IODA2 (P8), so I'll give a quick
>description here. Wei, feel free to copy/paste that into a bit of doco
>to throw into Documentation/powerpc/ along with your next spin of the patch.
>

Got it.

I will add more description in powerpc directory.


-- 
Richard Yang
Help you, Help me