Re: [PATCH v2 2/6] drm/ttm: Implement intersect/compatible functions

[Arunpravin Paneer Selvam <arunpravin.paneerselvam@amd.com>]

On 8/8/2022 5:00 PM, Christian König wrote:
>
>
> Am 25.07.22 um 13:42 schrieb Arunpravin Paneer Selvam:
>> Implemented a new intersect and compatible callback functions
>> to ttm range manager fetching start offset from drm mm range
>> allocator.
>>
>> Signed-off-by: Christian König <christian.koenig@amd.com>
>> Signed-off-by: Arunpravin Paneer Selvam 
>> <Arunpravin.PaneerSelvam@amd.com>
>> ---
>>   drivers/gpu/drm/ttm/ttm_range_manager.c | 33 +++++++++++++++++++++++++
>>   1 file changed, 33 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_range_manager.c 
>> b/drivers/gpu/drm/ttm/ttm_range_manager.c
>> index d91666721dc6..12b8d9b36fe6 100644
>> --- a/drivers/gpu/drm/ttm/ttm_range_manager.c
>> +++ b/drivers/gpu/drm/ttm/ttm_range_manager.c
>> @@ -113,6 +113,37 @@ static void ttm_range_man_free(struct 
>> ttm_resource_manager *man,
>>       kfree(node);
>>   }
>>   +static bool ttm_range_man_intersect(struct ttm_resource_manager *man,
>> +                    struct ttm_resource *res,
>> +                    const struct ttm_place *place,
>> +                    size_t size)
>> +{
>> +    struct drm_mm_node *node = 
>> &to_ttm_range_mgr_node(res)->mm_nodes[0];
>> +    u32 num_pages = PFN_UP(size);
>> +
>> +    /* Don't evict BOs outside of the requested placement range */
>> +    if (place->fpfn >= (node->start + num_pages) ||
>> +        (place->lpfn && place->lpfn <= node->start))
>> +        return false;
>> +
>> +    return true;
>> +}
>> +
>> +static bool ttm_range_man_compatible(struct ttm_resource_manager *man,
>> +                     struct ttm_resource *res,
>> +                     const struct ttm_place *place,
>> +                     size_t size)
>> +{
>> +    struct drm_mm_node *node = 
>> &to_ttm_range_mgr_node(res)->mm_nodes[0];
>> +    u32 num_pages = PFN_UP(size);
>> +
>> +    if (node->start < place->fpfn ||
>
> This should probably be "<=".
We are checking the false condition here, if node->start == place->fpfn, 
then the node->start
value is compatible with place->fpfn, therefore, we don't return false.

Thanks,
Arun
>
> Regards,
> Christian.
>
>> +        (place->lpfn && (node->start + num_pages) > place->lpfn))
>> +        return false;
>> +
>> +    return true;
>> +}
>> +
>>   static void ttm_range_man_debug(struct ttm_resource_manager *man,
>>                   struct drm_printer *printer)
>>   {
>> @@ -126,6 +157,8 @@ static void ttm_range_man_debug(struct 
>> ttm_resource_manager *man,
>>   static const struct ttm_resource_manager_func 
>> ttm_range_manager_func = {
>>       .alloc = ttm_range_man_alloc,
>>       .free = ttm_range_man_free,
>> +    .intersect = ttm_range_man_intersect,
>> +    .compatible = ttm_range_man_compatible,
>>       .debug = ttm_range_man_debug
>>   };
>