[Skiboot] [PATCH v8 20/24] MPIPL: Add OPAL API to query saved tags

[Vasant Hegde]

On 06/28/2019 07:16 AM, Nicholas Piggin wrote:
> Vasant Hegde's on June 17, 2019 3:10 am:
>> Pre-MPIPL kernel saves various information required to create vmcore in
>> metadata area and passes metadata area pointer to OPAL. OPAL will preserve
>> this pointer across MPIPL. Post MPIPL kernel will request for saved tags
>> via this API. Kernel also needs below tags:
>>    - Saved CPU registers data to access CPU registers
>>    - OPAL metadata area to create opalcore
>>
>> Format:
>>    opal_mpipl_query_tag(uint32_t idx, uint64_t *tag)
>>
>>    idx : tag index (0..n)
>>    tag : OPAL will pass saved tag
>>
>>    Kernel will make this call with increased `index` until OPAL returns
>>    OPAL_EMPTY.
>>
>> Return values:
>>    OPAL_SUCCESS   : Operation success
>>    OPAL_PARAMETER : Invalid parameter
>>    OPAL_EMPTY	 : OPAL completed sending all tags to kernel
> 
> Thanks for doing this API as well. I like giving the client the
> ability to just define their own metadata in preserved memory.

Thanks!

-Vasant