Re: [PATCH v7 14/50] powerpc/powernv: M64 support on P7IOC

Gavin Shan
2015-11-17T03:05:41Z

On Tue, Nov 17, 2015 at 01:37:22PM +1100, Alexey Kardashevskiy wrote:
>On 11/17/2015 12:42 PM, Gavin Shan wrote:
>>On Mon, Nov 16, 2015 at 07:02:18PM +1100, Alexey Kardashevskiy wrote:
>>>On 11/05/2015 12:12 AM, Gavin Shan wrote:
>>>>This enables M64 window on P7IOC, which has been enabled on PHB3.
>>>>Different from PHB3 where 16 M64 BARs are supported and each of
>>>>them can be owned by one particular PE# exclusively or divided
>>>>evenly to 256 segments, every P7IOC PHB has 16 M64 BARs and each
>>>>of them are divided to 8 segments. So every P7IOC PHB supports
>>>>128 M64 segments in total. P7IOC has M64DT, which helps mapping
>>>>one particular M64 segment# to arbitrary PE#. PHB3 doesn't have
>>>>M64DT, indicating that one M64 segment can only be pinned to the
>>>>fixed PE#. In order to have same code to support M64 on P7IOC and
>>>>PHB3, we just provide 128 M64 segments on every P7IOC PHB and each
>>>>of them is pinned to the fixed PE# by bypassing the function of
>>>>M64DT. In turn, we just need different phb->init_m64() for P7IOC
>>>>and PHB3 to support M64.
>>>
>>>I thought we decided (Ben suggested?) not to push P7IOC code now (or ever) as
>>>there is no user for it, has this changed?
>>>
>>
>>Remember that the code is mixed for P7IOC/PHB3. It's not harmful to support
>>M64 window on P7IOC, which is much larger than M32.
>
>
>The patchset starts with removing dead code and then adds more dead code.
>This is not right...
>

Sorry, you mean it's fine to break the code on P7IOC as it's going to be dead.
But I'm curious when it's going happen, any idea about that?

>>>btw please put ioda1/ioda2/p7ioc/etc to the subject line to make it easier to
>>>see how much work is there about particular PHB type. You rename quite many
>>>functions and I generally want to ask you to group all renaming patches first
>>>but it would also make sense to keep them close to (for example)
>>>p7ioc-related patches so having more descriptive subject lines may help.
>>>Thanks.
>>>
>>
>>As the code is mixed for P7IOC/PHB3, I'm not following the line (IODA1/IODA2/p7ioc/phb3)
>>in this patchset.
>
>But you should draw the bold line between PHB types imho.
>
>>Instead, the sequence of patchset is order related to: cod refactoring,
>>IO/M32/M64, DMA, PE allocation/releaseing.
>
>
>Some patches from this patchset are about P7IOC only. All I am asking is to
>say specifically in the subject line what the patch touches -
>IODA1/IODA2/p7ioc/phb3/all_of_them. Or I can walk through all of them, pick
>P7IOC's ones, evaluate the amount of code and entropy they actually add and
>then ask Ben what we do about it, it will just take longer rather than if you
>did it.
>

Please give me a clear command what key words you need in the subject in next revision.
What I understood is you want to see one of them:

powerpc/powernv/ioda1:
powerpc/powernv/ioda2:
powerpc/powernv/all:

Thanks,
Gavin

>
>--
>Alexey
>