[PATCH 1/4] drm/ttm: add TTM_PL_FLAG_TEMPORARY flag v3

[Thomas Hellström (Intel)]

Sure. LGTM,

Reviewed-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>


On 6/7/21 2:36 PM, Christian König wrote:
> Thomas any comments on this?
>
> Is the purpose of this now clear enough?
>
> Thanks,
> Christian.
>
> Am 01.06.21 um 14:25 schrieb Christian König:
>> From: Lang Yu <Lang.Yu at amd.com>
>>
>> Sometimes drivers need to use bounce buffers to evict BOs. While 
>> those reside
>> in some domain they are not necessarily suitable for CS.
>>
>> Add a flag so that drivers can note that a bounce buffers needs to be
>> reallocated during validation.
>>
>> v2: add detailed comments
>> v3 (chk): merge commits and rework commit message
>>
>> Suggested-by: Christian König <christian.koenig at amd.com>
>> Signed-off-by: Lang Yu <Lang.Yu at amd.com>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> ---
>>   drivers/gpu/drm/ttm/ttm_bo.c    | 3 +++
>>   include/drm/ttm/ttm_placement.h | 7 +++++--
>>   2 files changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
>> index 51a94fd63bd7..6b393502198e 100644
>> --- a/drivers/gpu/drm/ttm/ttm_bo.c
>> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
>> @@ -929,6 +929,9 @@ static bool ttm_bo_places_compat(const struct 
>> ttm_place *places,
>>   {
>>       unsigned i;
>>   +    if (mem->placement & TTM_PL_FLAG_TEMPORARY)
>> +        return false;
>> +
>>       for (i = 0; i < num_placement; i++) {
>>           const struct ttm_place *heap = &places[i];
>>   diff --git a/include/drm/ttm/ttm_placement.h 
>> b/include/drm/ttm/ttm_placement.h
>> index aa6ba4d0cf78..8995c9e4ec1b 100644
>> --- a/include/drm/ttm/ttm_placement.h
>> +++ b/include/drm/ttm/ttm_placement.h
>> @@ -47,8 +47,11 @@
>>    * top of the memory area, instead of the bottom.
>>    */
>>   -#define TTM_PL_FLAG_CONTIGUOUS  (1 << 19)
>> -#define TTM_PL_FLAG_TOPDOWN     (1 << 22)
>> +#define TTM_PL_FLAG_CONTIGUOUS  (1 << 0)
>> +#define TTM_PL_FLAG_TOPDOWN     (1 << 1)
>> +
>> +/* For multihop handling */
>> +#define TTM_PL_FLAG_TEMPORARY   (1 << 2)
>>     /**
>>    * struct ttm_place