[Skiboot] [PATCH v11 03/11] skiboot: Add chip id to HOMER reserved region

[Madhavan Srinivasan]

On Friday 12 May 2017 06:50 AM, Stewart Smith wrote:
> Madhavan Srinivasan <maddy at linux.vnet.ibm.com> writes:
>> From: Vasant Hegde <hegdevasant at linux.vnet.ibm.com>
>>
>> This patch adds a "ibm,chip-id" property to HOMER reserved region. That
>> helps us in relating the HOMER reserved region to the chip that its
>> associated with.
>>
>> This patch is required for nest IMC counters since, the counter values
>> are stored in an offset inside the HOMER region. To read those values
>> from the kernel for a chip, we need to associate the region to its
>> associated chip.
>>
>> Signed-off-by: Vasant Hegde <hegdevasant at linux.vnet.ibm.com>
>> Signed-off-by: Hemant Kumar <hemant at linux.vnet.ibm.com>
>> Signed-off-by: Madhavan Srinivasan <maddy at linux.vnet.ibm.com>
>> ---
>>   core/init.c       |  3 +++
>>   hw/homer.c        | 30 ++++++++++++++++++++++++++++++
>>   include/skiboot.h |  1 +
>>   3 files changed, 34 insertions(+)
> As mentioned in review of the kernel patch (see
> https://patchwork.ozlabs.org/patch/758583/ ) I think it woul be better
> that if instead of keying everything to /reserved-memory/ibm,homer-image
> we just provided a base address either directly in the IMC DT part or
> have a phandle reference to the reserved-memory region that's
> appropriate.
Yes. I agree. So can we add a chip node under /imc DT
to pass on this data. Something like this

     chip@<id> {
         base_addr = < addr >;
         ibm,chip-id = < id>;
     };

Maddy

>
> This would give us flexibility in the interface to the kernel, and not
> tie us to counters in the ibm,homer-image.
>
>