[PATCH v4 06/21] powerpc/powernv: Create PEs dynamically

Gavin Shan gwshan at linux.vnet.ibm.com
Mon May 11 14:55:13 AEST 2015

On Sat, May 09, 2015 at 09:43:16PM +1000, Alexey Kardashevskiy wrote:
>On 05/01/2015 04:02 PM, Gavin Shan wrote:
>>Currently, the PEs and their associated resources are assigned
>>in ppc_md.pcibios_fixup(). The function is called for once after
>>PCI probing and resources assignment are finished. Obviously, it's
>>not hotplug friendly. The patch creates PEs dynamically by
>>ppc_md.pcibios_setup_bridge(), which is called on the event during
>>system bootup and PCI hotplug: updating PCI bridge's windows after
>>resource assignment/reassignment are finished. For partial hotplug
>>case, where not all PCI devices belonging to the PE are unplugged
>>and plugged again, we just need unbinding/binding the affected
>>PCI devices with the corresponding PE without creating new one.
>Some PEs are already created dynamically (SRIOV). I'd suggest to make subject
>more specific.

Sure, will do.

>>Besides, it might require addtional resources (e.g. M32) to the
>>windows of the PCI bridge when unplugging current adapter, and
>>insert a different adapter if there is one PCI slot, which is
>>assumed behind root port, or the downstream bridge of the PCIE
>>switch behind root port. The parent bridge of the newly plugged
>>adapter would reject the request to add more resources, leading
>>to hotplug failure. For the issue, the patch extends the windows
>>of root port, or the upstream port of the PCIe switch behind root
>>port to PHB's windows when ppc_md.pcibios_setup_bridge() is called.
>>There is no upstream bridge for root bus, so we have to reserve
>>PE#, which is next to the reserved PE# in advance and fixing the
>>PE for root bus in ppc_md.pcibios_setup_bridge().
>>The patch also changes the rule assigning PE#: PE# reserved for
>>prefetchable 64-bits memory resource and SRIOV VFs starts from
>>zero while PE# for dynamic allocations starts from ioda.total_pe
>>reversely. It's because PE# for prefetchable 64-bits memory resource,
>>which is ually allocated begining with the PHB's aperatus and PE#

I need look into Chinese-English dictionary to confirm :-)

>May be it is just me but it looks like the patch moves existing bits and also
>adds this dynamic PE creation, cannot it be separated somehow into smaller
>patches as it is really hard to track all the changes you are making here?

It's good suggestion as I said in previous replies. Yeah, I'll see
if I can split it up to help review and bisecting.


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