[RFC 1/2] powerpc/mm: Add marker for contexts requiring global TLB invalidations

[Frederic Barrat]

Le 04/05/2017 à 08:41, Aneesh Kumar K.V a écrit :
> Frederic Barrat <fbarrat at linux.vnet.ibm.com> writes:
>
>> Introduce a new 'flags' attribute per context and define its first bit
>> to be a marker requiring all TLBIs for that context to be broadcasted
>> globally. Once that marker is set on a context, it cannot be removed.
>>
>> Such a marker is useful for memory contexts used by devices behind the
>> NPU and CAPP/PSL. The NPU and the PSL keep their own
>> translation cache so they need to see all the TLBIs for those
>> contexts.
>
> Can we also switch existing cxl_ctx_in_use() to this ?


That was my initial intent. But in the hash code, when calling the 
tlbie, it seems that we no longer have the related context handy. Or did 
I miss it? so it would require quite a bit of changes.

So I've just focused on fixing the pb for radix for the time being. That 
being said, we'll have to update what we do for hash if we ever want to 
support opencapi with hash/powervm (which seems like a strong 
possibility for next year), as we could have more than one opencapi drivers.

   Fred