[PATCH v3 05/12] drm/ttm: Expose ttm_tt_unpopulate for driver use

[Andrey Grodzovsky]

On 11/25/20 5:42 AM, Christian König wrote:
> Am 21.11.20 um 06:21 schrieb Andrey Grodzovsky:
>> It's needed to drop iommu backed pages on device unplug
>> before device's IOMMU group is released.
>
> It would be cleaner if we could do the whole handling in TTM. I also need to 
> double check what you are doing with this function.
>
> Christian.


Check patch "drm/amdgpu: Register IOMMU topology notifier per device." to see
how i use it. I don't see why this should go into TTM mid-layer - the stuff I do 
inside
is vendor specific and also I don't think TTM is explicitly aware of IOMMU ?
Do you mean you prefer the IOMMU notifier to be registered from within TTM
and then use a hook to call into vendor specific handler ?

Andrey


>
>>
>> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
>> ---
>>   drivers/gpu/drm/ttm/ttm_tt.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
>> index 1ccf1ef..29248a5 100644
>> --- a/drivers/gpu/drm/ttm/ttm_tt.c
>> +++ b/drivers/gpu/drm/ttm/ttm_tt.c
>> @@ -495,3 +495,4 @@ void ttm_tt_unpopulate(struct ttm_tt *ttm)
>>       else
>>           ttm_pool_unpopulate(ttm);
>>   }
>> +EXPORT_SYMBOL(ttm_tt_unpopulate);
>