Re: [PATCH] drm/ttm: Support 52-bit PAs in ttm_place

["Christian König" <christian.koenig@amd.com>]

On 5/13/26 16:15, Kuehling, Felix wrote:
> On 2026-05-13 03:08, Christian König wrote:
>>
>> On 5/13/26 00:31, Felix Kuehling wrote:
>>> fpfn and lpfn in struct ttm_place are 32-bit page numbers. With 4KB page
>>> size this can support up to 44-bit physical addressing. Grow these to
>>> unsigned long to support larger physical addresses.
>>>
>>> Signed-off-by: Felix Kuehling <felix.kuehling@amd.com>
>>> ---
>>>   include/drm/ttm/ttm_placement.h | 4 ++--
>>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/include/drm/ttm/ttm_placement.h b/include/drm/ttm/ttm_placement.h
>>> index b510a4812609..3e88869c0f58 100644
>>> --- a/include/drm/ttm/ttm_placement.h
>>> +++ b/include/drm/ttm/ttm_placement.h
>>> @@ -81,8 +81,8 @@
>>>    * Structure indicating a possible place to put an object.
>>>    */
>>>   struct ttm_place {
>>> -    unsigned    fpfn;
>>> -    unsigned    lpfn;
>>> +    unsigned long    fpfn;
>>> +    unsigned long    lpfn;
>> That should be uint64_t instead, long is CPU architecture dependent and we clearly don't want that in TTM.
>>
>> But apart from that looks reasonable to me.
> 
> Thanks. I sent out v2. What's the best branch for getting this change upstream? We'll need it on our NPI branch in the interim.

Arun will push it to drm-misc-next, if you also need it in amd-staging-drm-next you need to sync up with Alex. But that shouldn't be much of a problem.

Regards,
Christian

> 
> Regards,
>   Felix
> 
> 
>>
>> Regards,
>> Christian.
>>
>>>       uint32_t    mem_type;
>>>       uint32_t    flags;
>>>   };